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Showing papers on "Latent heat published in 1982"


Journal ArticleDOI
TL;DR: In this paper, an extensive act of sensible heat (Reynolds flux and dissipation methods) and latent heat (dissipation method) flux measurements from a stable deep water tower and from ships on the deep sea is presented.
Abstract: This papar presents an extensive act of sensible heat (Reynolds flux and dissipation methods) and latent heat (dissipation method) flux measurements from a stable deep water tower and from ships on the deep sea. Operational difficulties associated with ship spray and flow distortion and with sensor calibration, response and contamination are discussed. The influence of atmospheric stability on the dissipation measurements and the bulk transfer coefficients is considered and a parameterization of Z/ L in terms of wind speed and the sea-air potential temperature difference is found to be adequate. Temperature variances, Stanton numbers and w–t cospectra from the Roynolds flux measurements are compared to previous results. The dissipation method is shown to be a viable means of measuring the heal fluxes over the deep sea by comparison with simultaneous Reynolds flux measurements, using our data for the sensible heat and the data of others for the latent heat. The neutral drag coefficient at 10 m hei...

783 citations


Journal ArticleDOI
Carlos G. Levi1, R. Mehrabian
TL;DR: In this paper, a new mathematical formulation and solution methodology is developed for simulating the solidification process in an undercooled spherical droplet from a single nucleation event occurring at its surface.
Abstract: The solidification of undercooled spherical droplets with a discrete melting temperature is analyzed using both a Newtonian and a non-Newtonian (Enthalpy) model. Relationships are established between atomization parameters, the growth kinetics, the interface velocity and undercooling, and other important solidification variables. A new mathematical formulation and solution methodology is developed for simulating the solidification process in an undercooled droplet from a single nucleation event occurring at its surface. The computational mesh used in the enthalpy model is defined on a superimposed bispherical coordinate system. Numerical solutions for the solidification of pure aluminum droplets based on the enthalpy model are developed, and their results are compared to the trends predicted from the Newtonian model. The implications of single vs multiple nucleation events are also discussed. In general, the results indicate that when substantial undercoolings are achieved in a droplet prior to nucleation, the thermal history consists of two distinct solidification regimes. In the first, the interface velocities are high, the droplet absorbs most of the latent heat released, and the external cooling usually plays a minor role. The second regime is one of slower growth, and strongly depends on the heat extraction at the droplet surface. The extent of “rapid solidification”, as determined from the fraction of material solidified at temperatures below a certain critical undercooling, is a function of the nucleation temperature, the particle size, a kinetic parameter, and the heat translow as 10~4.

224 citations


Journal ArticleDOI
TL;DR: In this article, the Bowen ratio energy balance method often produces totally unacceptable sensible and latent heat fluxes: wrong signs (directions) and extremely inaccurate magnitudes of the fluxes, or both.
Abstract: In addition to the inherent problem of accumulating errors of measurement of net radiation and subsurface heat flux, the Bowen ratio energy balance method often produces totally unacceptable sensible and latent heat fluxes: wrong signs (directions) and extremely inaccurate magnitudes of the fluxes, or both. These problems are due to resolution limits of the instruments. Objective criteria to eliminate undesirable data are derived in general forms. An example is graphically presented for the common case of the psychometric tower with a 0.05°C resolution limit of temperature measurement.

218 citations


Journal ArticleDOI
TL;DR: In this article, a comparison between two methods for determining the surface fluxes of sensible and latent heat during daytime was made, and the results showed that the simple parameterization is preferred for practical purposes.
Abstract: A comparison is made between two methods for determining the surface fluxes of sensible and latent heat during daytime. The first method, known as the Penman-Monteith approach, incorporates a more complete description of the physics. However, it needs a relatively large number of input parameters, which is inconvenient in many applications. The second method is a modification of the Priestley-Taylor evaporation model, which needs only net radiation, air temperature and an indication of the moisture condition at the surface. Both models are compared on the basis of hourly micro-meteorological data above short grass obtained in the Netherlands during the summer of 1977. The experiments were performed under predominantly unstable conditions [0 ≥ z/L0 ≥ −0.3z = (mean) measuring height, L0 = Obukhov length] with weak or no advection. It appears that, under these environmental conditions, the models have a similar skill. Therefore, the simple parameterization is preferred for practical purposes. It rev...

200 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the turbulence profiles and budgets for two days of radiation, dynamical and thermodynamical observations by the NCAR Electra in shallow marine stratocumulus off the California coast in June 1976.
Abstract: This paper discusses the turbulence profiles and budgets for two days of radiation, dynamical and thermodynamical observations by the NCAR Electra in shallow marine stratocumulus off the California coast in June 1976. The boundary layer is characterized by relatively high wind speeds (12–20 m s−1) and low liquid water contents (0.1 g kg−1); the clouds are not very convective and seem to have little influence on the turbulence budgets. In cloud, drizzle has a significant impact on the liquid water budget and occasionally even on the total water budget even though no drizzle is observed at the surface. The stresses, velocity variances, and their budgets behave as in a neutral boundary layer, sometimes with an additional peak in the cross-wind variance at the inversion due to shear production. There is scant evidence of direct production of vertical velocity variance at cloud top due to radiative cooling or latent heat release; it is maintained principally by the pressure-scrambling terms through re...

163 citations


Journal ArticleDOI
TL;DR: In this paper, an analytical study of the heat and mass transfer process of a single particle exposed to a thermal plasma, with emphasis on the effects which evaporation imposes on heat transfer from the plasma to the particle, is presented.
Abstract: This paper is concerned with an analytical study of the heat and mass transfer process of a single particle exposed to a thermal plasma, with emphasis on the effects which evaporation imposes on heat transfer from the plasma to the particle. The results refer mainly to an atmospheric-pressure argon plasma and, for comparison purposes, an argon-hydrogen mixture and a nitrogen plasma are also considered in a temperature range from 3000 to 16,000 K. Interactions with water droplets, alumina, tungsten, and graphite particles are considered in a range of small Reynolds numbers typical for plasma processing of fine powders. Comparisons between exact solutions of the governing equations and approximate solutions indicate the parameter range for which approximate solutions are valid. The time required for complete evaporation of a given particle can be determined from calculated values of the vaporization constant. This constant is mainly determined by the boiling (or sublimation) temperature of the particles and the density of the condensed phase. Evaporation severely reduces heat transfer to a particle and, in general, this effect is more pronounced for materials with low latent heat of evaporation.

112 citations


Journal ArticleDOI
TL;DR: In this article, a general formulation to express the different heat fluxes as a function of net radiation is proposed, which can be expressed as a sum of three terms: the first indicates a direct proportionality to Φ, the second gives the deviation from linearity and depends on ∂Φ/∂t, and the third gives the value of the flux when Φ = 0.
Abstract: Experimental evidence indicates that the diurnal behaviour of the fluxes of heat into the ground and into the atmosphere versus the net flux of radiation can be modelled by closed curves, the hourly values folowing one another in either a clockwise or counter clockfashion A general formulation to express the different heat fluxes as a function of net radiation Φ is proposed This relationship between the different heat fluxes and Φ can be expressed as a sum of three terms: the first indicates a direct proportionality to Φ, the second gives the deviation from linearity and depends on ∂Φ/∂t, and the third gives the value of the flux when Φ = 0 The formulae are then expressed as a function of time and the ratios between the heat fluxes and Φ are evaluated A comparison with the approximations generally used shows that the latter may be considered as particular cases of the more general equations proposed here

94 citations


Journal ArticleDOI
TL;DR: In this article, the shallow water equations are supplemented by a moisture equation in order to model effects of latent heat release on the horizontal propagation of disturbances, since latent heating in regions of upward motion compensates the reduction in perturbation temperature due to lifting.
Abstract: The shallow-water equations are supplemented by a moisture equation in order to model effects of latent heat release on the horizontal propagation of disturbances. Since latent heating in regions of upward motion compensates the reduction in perturbation temperature due to lifting, buoyancy effects are reduced and disturbances propagate more slowly. Analytic solutions are obtained to illustrate this effect, a good example being provided by the collapse of an initial horizontal temperature discontinuity. Another interesting example is provided by the case of disturbances propagating through a region from one side. Moist regions are found to have front and rear boundaries which both move faster than rainbands do inside the moist region. If random disturbances are passed through a region which is initially saturated, the relative humidity drops until it reaches a value which depends on the disturbance level.

89 citations


Journal ArticleDOI
TL;DR: In this paper, the authors measured CO2 densities over an arid, vegetation-free surface by eddy covariance techniques and by a heat budget-profile method, in which CO2 concentration gradients were specified in terms of mixing ratios.
Abstract: Flux densities of carbon dioxide were measured over an arid, vegetation-free surface by eddy covariance techniques and by a heat budget-profile method, in which CO2 concentration gradients were specified in terms of mixing ratios. This method showed negligible fluxes of CO2, consistent with the bareness of the experimental site, whereas the eddy covariance measurements indicated large downward fluxes of CO2. These apparently conflicting observations are in quantitative agreement with the results of a recent theory which predicts that whenever there are vertical fluxes of sensible or latent heat, a mean vertical velocity is developed. This velocity causes a mean vertical convective mass flux (= ρ cw for CO2, in standard notation). The eddy covariance technique neglects this mean convective flux and measures only the turbulent flux ρ′ c w′. Thus, when the net flux of CO2 is zero, the eddy covariance method indicates an apparent flux which is equal and opposite to the mean convective flux, i.e., ρ′ c w′ = −ρ c w. Corrections for the mean convective flux are particularly significant for CO2 because ρ cw and ρ′ c w′ are often of similar magnitude. The correct measurement of the net CO2 flux by eddy covariance techniques requires that the fluxes of sensible and latent heat be measured as well.

87 citations


Journal ArticleDOI
TL;DR: In this paper, the energy balance on the arctic tundra on the midwest coast of Axel Heiberg Island, N.W.T., Canada, is analyzed for dry snow, the melt and the postmelt periods.
Abstract: Energy balance measurement on the arctic tundra on the midwest coast of Axel Heiberg Island, N.W.T., Canada, is summarized. The methods and the instruments as well as their difficulties in the arctic field conditions are described. The seasonal characteristics of the energy balance are presented for the dry snow, the melt and the postmelt periods. The diurnal variations of the energy balance for each of these periods are also presented. The climatic differences for the regions of the tundra, glaciers and the arctic seas become prominent during the three summer months of June, July and August. The energy balance at the present site is compared with that of Barrow, Alaska, revealing a high degree of similarity. The slight differences between them are more net radiation, more sensible and latent heat fluxes, larger Bowen ratio and less soil heat flux at Barrow. These differences are considered to be due to the larger distance of the present station from the coast. The energy balance on and in the dry snow cover is investigated. The stability of the snow cover is attributed to the high reflectivity as well as to the large absorptivity of its surface with respect to solar radiation. The absorption occurs mainly at the surface of the snow cover rather than its interior. This condition facilitates the efficient removal of the absorbed energy from the surface by the atmosphere. The energy balance on the tundra is compared with those on the Central Arctic Ocean, the ablation area of the polar glaciers, the accumulation area of the glaciers and the boreal forests. The surfaces of the tundra, ablation area of the glaciers and the Central Arctic Ocean are found to receive similar net radiation, despite the albedo differences. The fundamental difference among these surfaces is the magnitude of the latent heat of melt. This component on the ablation area of the glaciers and the Central Arctic Ocean is four to six times larger than on the tundra, which results in differential heating and evaporation in these regions. This difference is considered to be the basis of the milder climate in the tundra region in the Arctic. More substantial differences are found between these low altitude arctic surfaces and the accumulation areas of the glaciers and the boreal forests. The differences are due to the large variation in albedo for the former and to the difference in global radiation for the latter. These differences ultimately regulate the regional variations in net radiation, sensible and latent heat fluxes.

86 citations



Journal ArticleDOI
TL;DR: In this paper, a numerical one-dimensional model was designed to simulate the diurnal changes of the greenhouse en-vironment The model consists of: a soil layer, a vegeta-tion layer, an air layer and a cover The thermal radiative, sensible, latent and conductive heat fluxes were modeled in each layer in terms of its unknown temperature and vapor pressure.
Abstract: A numerical one-dimensional model was designed to simulate the diurnal changes of the greenhouse en-vironment The model consists of: a soil layer, a vegeta-tion layer, an air layer and a cover The thermal radiative, sensible, latent and conductive heat fluxes were modeled in each layer in terms of its unknown temperature and vapor pressure In order to obtain flexibility and accuracy of the model, sophisticated models were adopted to simulate each of the greenhouse sublayers and a theoretical method was proposed to describe the water diffusion through stomata as a function of the environmental parameters Numerical experiments were conducted to test the sen-sitivity of the model to some parameters The results in-dicate the necessity to properly initialize the model and to determine an accurate inside air transfer coefficient of sensible and latent heat An observational study was performed in order to test the ability of the model to properly describe the greenhouse microclimate Good agreement was obtained between predicted and observed temperatures and humidities

Journal ArticleDOI
TL;DR: In this article, the authors applied conditional sampling to aircraft turbulence measurements in order to study updrafts and downdrafts over the central equatorial Pacific Ocean, and found that updraft are usually cool/moist and warm/modal while downdavs are most often warm/dry.
Abstract: Conditional sampling has been applied to aircraft turbulence measurements in order to study updrafts and downdrafts over the central equatorial Pacific Ocean. Average event size, number density and proportion of time series occupied are obtained for the drafts, along with conditional averages of horizontal momentum, moisture and virtual temperature and the draft contributions to the total fluxes. It is found that updrafts are usually cool/moist and warm/moist while downdrafts are most often warm/dry. Convective mass flux parameterizations of the sensible and latent heat flux are tested. Results consistent with previous workers are obtained when the flux production is mainly by updrafts. However, when downdrafts dominate, they must be taken into account explicitly in order for the parameterization to be accurate.


Journal ArticleDOI
TL;DR: In this article, a model for surface resistance for evaporation is presented, which is related to net radiation and to accumulated net radiation since last precipitation, which determines the degree of dryness of the soil.
Abstract: A method is described for evaluation of hourly values of the sensible heat flux from routine meteorological data. Use is made of the energy balance at the surface and of the Monteith-Penman formula for estimation of the latent heat flux. The soil heat flux is modelled as a given fraction of the sensible heat flux. The net radiation is computed from the information on cloudiness and solar elevation. A model for surface resistance for evaporation is presented. It is shown that the surface resistance correlates well with the atmospheric humidity deficit. Furthermore, the surface resistance is related to net radiation and to accumulated net radiation since last precipitation. The accumulated net radiation determines the degree of dryness of the soil. The model results of surface resistance and sensible heat flux are compared with experimental data from three sites: Hobakkegaard, Denmark; Marsta, Sweden; and Cabauw, Holland. The comparison is satisfactory and encourages the use of the method for routi...

Journal ArticleDOI
TL;DR: In this paper, phase boundaries are represented by point chains which act as additional sources of buoyancy forces when distorted, and as additional source or sink of heat in both shallow and deep convection models.
Abstract: Summary. Phase boundaries are included in dynamical finite element models of mantle convection. They are represented by point chains which act as additional sources of buoyancy forces when distorted, and as additional source or sink of heat. The influence of the exothermic olivine-spinel transition is studied in both shallow and deep convection models. The flow is only slightly enhanced by the transition. The increase of temperature due to latent heat release is step-like in the deep model, in the case of shallow convection it is more diffuse. Other quantities like ocean-floor topography, gravity anomalies, and stress distribution are no more than moderately affected. In a further investigation the effect of spinel post-spinel transition, whether endothermic or exothermic, on deep convection is examined. The effect on the flow is negligibly small in both cases.

Journal ArticleDOI
TL;DR: In this paper, a method for estimating the heat and moisture fluxes of coastal waters using the cloud free path, the sea surface temperature, and the saturation water vapor mixing ratio is presented.
Abstract: A method for estimating the heat and moisture fluxes of coastal waters using the cloud free path, the sea surface temperature, and the saturation water vapor mixing ratio is presented. Generalized nomograms for the surface sensible and latent heat fluxes are developed using the Stage and Businger (1981) mixed-layer model. The fluxes are found to be slightly dependent on wind speed. The results are found to be applicable to any path within the cloud-free region, with heat fluxes obtainable by multiplication of the mean heating by the mean wind speed in the boundary layer. Higher stability causes lowered heating. It is shown that the latent heat flux is linear. Applications of the method to lake-effect snowstorms and for verification of boundary-layer models are indicated.

Journal ArticleDOI
TL;DR: Results indicate no discernible effect for cool temperatures, but for warm temperatures it appears that increased growth rates may be accompanied by an approximately proportional increase in specific sensible heat production.

Journal ArticleDOI
TL;DR: In this paper, an effort is made to clarify the issue and to sketch what its importance is to the energy balance of the hydrological cycle, and it is found that a good first-order approximation shows that no corrections are necessary, which is in agreement with Frank and Emmitt's result.
Abstract: Corrections to the sensible heat flux due to fluctuations in the specific humidity recently proposed by Brook (1978) have been shown to be incorrect by Frank and Emmitt (1981). However, it is easy to misinterpret Frank and Emmitt’s paper. Here an effort is made to clarify the issue and to sketch what its importance is to the energy balance of the hydrological cycle. By expanding the specific enthalpy flux into the fluxes of sensible heat and latent heat, it is found that a good first-order approximation shows that no corrections are necessary, which is in agreement with Frank and Emmitt's result.

Journal ArticleDOI
TL;DR: In this article, the effects of latent heating on the development of a wave cyclone were investigated using a multi-level primitive equation model to simulate the cyclone system with (wet) and without (dry) latent heating.
Abstract: The effects of latent heating on the development of a wave cyclone are investigated using a multi-level primitive equation model to simulate the cyclone system with (wet) and without (dry) latent heating. While the dry simulation failed to properly predict either the formation of the closed circulation which developed throughout the depth of the troposphere or the pronounced northwest-to-southeast horizontal tilt of the upper-level trough shown by observations, the wet simulation successfully reproduced both these features. The mechanisms for the generation of the regional-scale closed system are examined and the influence of latent heating on large-scale dynamics and energetics is discussed. Results indicate that latent heat release stabilized the troposphere and reduced the large-scale horizontal temperature gradient. Also, through the enhancement of ageostrophic flow, the addition of latent heat generated kinetic energy in both the lower and upper troposphere at the expense of the available po...

Journal ArticleDOI
TL;DR: In this paper, the heat and ice balances of a temperate sub-Antarctic cirque glacier were measured through the 1973-74 melt season at an altitude midway between the climatic firn limit and the snout.
Abstract: The heat and ice balances of a temperate sub-Antarctic cirque glacier were measured through the 1973–74 melt season at an altitude midway between the climatic firn limit and the snout. The melt calculated from mean daily measurements at a single level of net radiation, wind-speed, temperature, and humidity agreed with that observed at nearby budget stakes. In the central ablation zone, radiation provided (54 ± 6)% and sensible fluxes (46 ± 6)% of the heat income through the summer, which was exceptionally warm and sunny. Latent-heat fluxes made no significant contribution to the heat balance. The calculation by Smith (1960) that the radiative, sensible, and latent heat fluxes contribute about equally to ablation in this zone has not been substantiated by measurement. The measured partition of the glacier’s heat balance suggested that maritime influences on its regime are mitigated by its position in the lee of a major mountain range.

Patent
08 Mar 1982
TL;DR: In this paper, a bag-like container and a spherical container in which a latent heat accumulating material is enclosed, and a heat accumulating apparatus employing such containers are described, respectively.
Abstract: The present invention relates to a bag-like container, and a spherical container in which a latent heat accumulating material is enclosed, and a heat accumulating apparatus employing such containers. A heat accumulating mat material (A) is of a flat bag-like container divided into a plurality of sections, where a latent heat accumulating substance is enclosed. A spherical container (1A) has a heat transfer area enlarging portion of a recess (102), a groove (103). A solar heat accumulating greenhouse 2A has a radiator heat exchanging portion (2B, 2D), a heat accumulating tank 2C and a forced circulation liquid system.

Journal ArticleDOI
TL;DR: In three separate tests Glauber's salt in a rolling cylinder was subjected to 126, 203 and 198 melt-freeze cycles as mentioned in this paper, and all three tests gave the same results: 100 per cent of the theoretical latent heat was recovered within experimental error (± 5 per cent), and no degradation of performance occurred with repeated cycling.

01 Jan 1982
TL;DR: In this article, the energy balance of the earth's surface with a special emphasis on practical applications is studied. But the authors focus on the evaporation process and do not consider the other energy sources, such as the sun, clouds, water vapour, and CO 2.
Abstract: This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This radiation originates partly from the sun, but an~ other fraction is coming from the atmosphere (= infra-red radiation emitted by clouds, water vapour and CO 2 ). From these gain terms the following losses must be subtracted: (a) the reflected solar radiation and (b) the infra-red radiation emitted by the surface itself. The final result is that a net amount of radiant energy is received by the surface, simply denoted as net radiation. At the ground net radiation is used to heat the ground (soil heat flux), to evaporate liquid water (evaporation), and to heat the atmosphere (sensible heat flux). In this simple picture we have neglected minor terms such as the energy used by the plants for their photosynthesis. Due to the high value of the latent heat of vaporization, the energy needed for evaporation is often an important term in the energy balance. In addition the energy balance of the earth's surface is linked with the water budget of both the atmosphere and the earth's surface, through the evaporation at the ground. Several practical questions in agriculture, hydrology and meteorology require information m the energy balance of the surface. It is the purpose of this study to find solutions for some of these problems. In hydrology one is mainly concerned in evaporation averaged over 1 day or more on a regional scale. Generally, this refers to land surfaces, but the evaporation of inland lakes or reservoirs is also of interest. In this context we also mention the problem of thermal pollution of open water bodies by industry or power plants. For this the so-called natural water temperature must be known, which is the temperature of the water in the hypothetical case that there is no artificial heating. It appears that this temperature depends mainly m the energy balance at the surface. In Chapter VI a model dealing with this problem is discussed. In agriculture one is interested also in evaporation. Now time intervals ranging from half an hour to several days are of interest. The relation between evaporation an the one side and plant diseases and pest control an the other can be mentioned. Furthermore, the yield of several agricultural crops is the greatest when the evapotranspiration is potential (= a maximum under the given weather conditions). When the crop transpires less than the potential rate, because the soil is too dry, the yield can be augmented by artificial precipitation. For applications such as these cheap and simple techniques are required for measuring the actual and potential evaporation. This applies also to agricultural research projects, e.g. to determine yield-water use relationships. In Chapter II simple measurement techniques are considered. Recent developments in meteorology have led to an increase of the interest in the energy balance of the earth's surface, especially in the input of heat and humidity at ground level into the atmosphere. Examples are models for the atmospheric boundary layer and related models for short range weather forecasts (12-18 h ahead). These models require simple parameterizations of the surface fluxes. This applies also to weather forecast models on a medium time range (3-10 days ahead). Since the height of the boundary layer is related to the heat input at the ground information an the surface energy balance is needed also for air pollution problems. In Chapter III a simple parameterization for evaporation and sensible heat flux is described that can be used for these type of problems. Usually, the only available data are standard weather observations. For that reason, many of the practical questions, mentioned above, can be formulated as: "How can the surface energy balance be estimated from standard weather data only'?" In Chapters III and VI possible answers to that question are discussed. Chapter II is devoted to simple measuring techniques that, in principle, can be used on an operational base. These methods will be compared with the so-called energy-balance method, using Bowen's ratio. In Chapter III two models for evaporation and sensible heat flux during daytime are compared. Both require standard weather data as input and an indication of the surface wetness. The first model needs more data, but contains more physics. The second is less complete, but requires less input data. Chapter IV has a mainly theoretical character. A model is presented that couples the evolution of the atmospheric boundary layer to the surface energy balance. It describes the course of the height, temperature and humidity of the boundary layer, together with the surface fluxes, when the initial profiles of temperature and humidity the radiative forcing and the surface wetness are known. It is restricted to convective conditions. Model output will be compared with observations. In Chapter V an empirical evaporation model for open water is considered. Comparisons with observations of evaporation of the former Lake Flevo will be made; the annual and the diurnal cycle will be considered. In Chapter VI a model for the (natural) temperature and energy balance of inland lakes and water reservoirs is discussed that requires standard weather data only. A comparison between the calculated and measured water temperature will be given. This concerns two adjacent water reservoirs, which have about the same size, but which differ in depth (5 and 15 m). This is of importance, since the water temperature also depends on water depth. At some places we made new modifications, but most of the theoretical concepts applied in this study are adopted from literature. This is inherent in our practical approach. Some of the theories used have been available for many years. But, e.g. because no suitable instruments were available, they were not usefull for practical applications. Recent developments in the field of instrumentation and data handling have changed the situation-to our advantage. A good example is the temperature fluctuation method for measuring the sensible heat flux (discussed in 11.4). The theoretical basis for this approach was given by Prandtl already in 1932. But for an experimental verification we had to wait until the sixties and early seventies. In that period instruments were developed to measure turbulent surface fluxes and fast temperature fluctuations, while also the data handling techniques were improved significantly. Finally) the method wouldn't be operationally until quite recently. For the verification of the parameterizations, measuring techniques and models treated in this study, we used data collected at the 200 m mast at Cabauw, and at the nearby micrometeorological field, of the Royal Netherlands Meteorological Institute.

Patent
09 Apr 1982
TL;DR: In this paper, a latent heat type heat accumulator, which stores and releases heat by means of phase change, is proposed to enable efficiently dissolve heat storage material during heating by a structure wherein heating is performed by providing heating sources, one of which covers the bottom surface and the other of which is vertical to bottom surface, at the lower part of the heat storage device.
Abstract: PURPOSE:To enable to efficiently dissolve heat storage material during heating by a structure wherein heating is performed by providing heating sources, one of which covers the bottom surface and the other of which is vertical to the bottom surface, at the lower part of the heat storage device in a latent heat type heat accumulator, which stores and releases heat by means of phase change. CONSTITUTION:The heat storage device A consists of the heat accumulator 1, the heat storage material 2, a heat exchanger 13 for heating and a radiator 4 for taking-out heat. The heat exchanger 131 for heating, which covers the whole bottom surface 6, and the heat exchanger 132 for heating, which is vertical to the bottom surface 6, integrally constitute the heat exchanger 13 for heating. During the initial stage of dissolution of the heat storage material, the heat storage material 12 is dissolved at the central portion of the heat accumulator 1 by means of the heat exchanger 132 for heating on a form so as to pierce the heat accumulator 1, resulting in leaving undissolved heat storage material 22 on the upper wall surface in the heat accumulator 1. The undissolved heat storage material 22 is dissolved by obtaining heat from dissolved heat storage material 12 lying in the bottom and the central portions of the heat accumulator 1 and developing the convection of the dissolved heat storage material throughout the whole portion of the heat accumulator 1.

Patent
12 Mar 1982
TL;DR: In this paper, a heat exchanger is provided in the drying chamber, and while air is prevented from entering the chamber, vapor or gas given off by the material is extracted from the chamber and at least some of that vapor or gases is compressed.
Abstract: The invention provides both a method and apparatus for drying moisture-containing materials, in which the material is dried in a drying chamber. A heat exchanger is provided in the drying chamber, and while air is prevented from entering the chamber, vapor or gas given off by the material is extracted from the chamber, at least some of that vapor or gas is compressed, and the compressed vapor or gas is passed through the heat exchanger, so that at least part of the latent heat of evaporation of the vapor or gas at the increased pressure is used to create the necessary temperature gradient between the heat exchanger and the atmosphere within the drying chamber, to cause the heat emission required for drying the material.

Journal ArticleDOI
TL;DR: In this paper, a NOAA P-3 research aircraft during flights over the eastern equatorial Pacific Ocean is used to obtain mean vertical profiles of water vapor density, potential temperature, wind speed and fluxes of latent heat, buoyancy and momentum.
Abstract: Turbulence data obtained aboard a NOAA P-3 research aircraft during flights over the eastern equatorial Pacific Ocean are used to obtain mean vertical profiles of water vapor density, potential temperature, wind speed and fluxes of latent heat, buoyancy and momentum. The variation of eddy fluxes and bulk transfer coefficients as a function of atmospheric stability are plotted for two of the flights. The observed transfer coefficients generally agree with those obtained from parameterizations based on surface-layer similarity theory (Deardorff, 1968; Kondo, 1975).

Patent
02 Jun 1982
TL;DR: In this paper, the authors proposed a method to improve the heat exchange efficiency of the heat pipe with respect to water in a hot water storage tank by a method wherein the hot water tank of a large capacity is divided into a plurality of sub-tanks of small capacity.
Abstract: PURPOSE:To improve the heat exchange efficiency of the heat pipe with respect to water in a hot water storage tank by a method wherein the hot water storage tank of a large capacity is divided into a plurality of sub-tanks of small capacity so that the heat exchange between a condensing section of the heat pipe and the water is performed within the sub-tanks. CONSTITUTION:The sunlight passed through a glass body 10 boils an operating liquid at an evaporation section 3a within the heat pipe 3. In this case, the latent heat of evaporation of the operating liquid is adsorbed at the evaporation section 3a and is discharged at the condensing section 3b to thereby heat the water 5 in the sub-tanks 11. Thus, when the water 5 in the sub-tanks is heated to a high temperature, the specific gravity of the water becomes small so that the water flows into the hot water storage tank 2 from a forward pipe 13 and an inlet port 15 through a hose 17 due to a convection phenomenon. At the same time, the low temperature hot water in the tank 2 passes through a hose 18 from an outlet port 6 and flows into the sub-tanks 11 from a return port 14.

Patent
08 Sep 1982
TL;DR: In this article, a heat-storing vessel with a gelling agent to suppress a phase separation phenomenon is presented, and a low temperature part is provided at a part of the heat storing vessel and the heatstoring material containing the geling agent is retained in a solid state at the low-temperature part to prevent supercooling.
Abstract: A heat-storing vessel filled with a heat-storing material of latent heat type is provided with a fluid flow passage in thermal contact with the heat-storing material for passing a fluid for storing and releasing heat. By passing a hot fluid through the fluid flow passage, the heat-storing material in the heat-storing vessel is melted to store heat. By passing a cold fluid through the fluid flow passage, the heat-storing material in the heat-storing vessel is solidified to release heat. The heat-storing material contains a gelling agent to suppress a phase separation phenomenon. A low temperature part is provided at a part of the heat-storing vessel and the heat-storing material containing the gelling agent is retained in a solid state at the low temperature part to prevent supercooling of the heat-storing material.

Patent
06 Aug 1982
TL;DR: In this article, a latent heat accumulator consisting of a plurality of sealed cells of small dimensions, filled with a chemical compound having a high latent melting heat, is described, and the cells are formed from a plastic thermo-formable material, with high thermal conductivity and gasproof as well as steamproof.
Abstract: The invention relates to a latent heat accumulator formed of a plurality of sealed cells (c) of small dimensions, filled with a chemical compound having a high latent melting heat. The cells are formed from a plastic thermoformable material, with high thermal conductivity and gasproof as well as steamproof. The cells are produced sealed, so as to prevent any outlet of the chemical compound or of its vapours. The heat is stored under form of latent heat and the melting temperature of the chemical compound is selected in function of the average temperature of the heat source being utilized.