Showing papers in "Journal of Heat Transfer-transactions of The Asme in 1991"

Augmented Heat Transfer in Square Channels With Parallel, Crossed, and V-Shaped Angled Ribs

Abstract: The effect of the rib angle orientation on the local heat transfer distributions and pressure drop in a square channel with two opposite in-line ribbed walls was investigated for Reynolds numbers from 15,000 to 90,000. The square channel composed of ten isolated copper sections has a length-to-hydraulic diameter ratio of 20; the rib height-to-hydraulic diameter ratio is 0.0625; the rib pitch-to-height ratio equals 10. Nine rib configurations were studied: 90 deg rib, 60 and 45 deg parallel ribs, 60 and 45 deg crossed ribs, 60 and 45 deg V-shaped ribs, and 60 and 45 deg {Lambda}-shaped ribs. The results show that the 60 deg (or 45 deg) V-shaped rib performs better than the 60 deg (or 45 deg) parallel rib and, subsequently, better than the 60 deg (or 45 deg) crossed rib and the 90 deg rib. The V-shaped rib produces the highest heat transfer augmentation, while the {Lambda}-shaped rib generates the greatest pressure drop. The crossed rib has the lowest heat transfer enhancement and the smallest pressure drop penalty.

The weighted-sum-of-gray-gases model for arbitrary solution methods in radiative transfer

Abstract: The weighted-sum-of-gray-gases approach for radiative transfer in nongray participating media, first developed by Hottel in the context of the zonal method, has been shown to be applicable to the general radiative equation of transfer Within the limits of the weighted-sum-of-gray-gases model (nonscattering media within a black-walled enclosure), any nongray radiation problem can be solved by any desired solution method after replacing the medium by an equivalent small number of gray media with constant absorption coefficients Some examples are presented for isothermal media and media at radiative equilibrium, using the exact integral equations as well as the popular P-1 approximation for the equivalent gray media solutions The results demonstrate the equivalency of the method with the quadrature of spectral results, as well as the tremendous computer times savings (by a minimum of 95 percent) that are achieved

Local Heat Transfer Coefficients Under an Axisymmetric, Single-Phase Liquid Jet

Abstract: The purpose of this investigation was to characterize local heat transfer coefficients for round, single-phase free liquid jets impinging normally against a flat uniform heat flux surface. The problems parameters investigated were jet Reynolds number Re, nozzle-to-plate spacing z, and jet diameter d. A region of near-constant Nusselt number was observed for the region bounded by 0 {le} r/d {le} 0.75, where is the radical distance from the impingement point. The local Nusselt number profiles exhibited a sharp drop for r/d > 0.75, followed by an inflection and a shower decrease thereafter. Increasing the nozzle-to-plate spacing generally decreased the heat transfer slightly. The local Nusselt number characteristics were found to be dependent on nozzle diameter. This was explained by the influence of the free-stream velocity gradient on local heat transfer, as predicted in the classical analysis of infinite jet stagnation flow and heat transfer. Correlations for local and average Nusselt numbers reveal an approximate Nusselt number dependence on Re{sup 1,3}.

Surface Curvature Effect on Slot-Air-Jet Impingement Cooling Flow and Heat Transfer Process

Abstract: Experiments are performed to study 'surface curvature effects on the impingement cooling flow and the heat transfer processes over a concave and a convex surface. A single air jet issuing from different size slots continuously impinges normally on the concave side or the convexside of a heated semicylindrical surface. An electrical resistance wire is used to generate smoke, which allows us to visualize the impinging flow structure. The local heat transfer Nusselt number along the surfaces is measured. For impingement on a convex surface, three-dimensional counterrotating vortices on the stagnation point are initiated, which result in the enhancement of the heat transfer process. For impingement on a concave surface, the heat transfer Nusselt number increases with increasing surface curvature, which suggests the initiation of Taylor-Gortler vortices along the surface. In the experiment, the Reynolds number ranges from 6000 to 350,000, the slot-to-plate spacing from 2 to 16, and the diameter-to-slot-width ratio D/b from 8 to 45.7. Correlations of both the stagnation point and the average Nusselt number over the curved surface, which account for the surface curvature effect, are presented. 1 Introduction Impingement cooling has been widely used to cool a heat transfer component exposed to a high temperature or a high heat flux environment. The impingement cooling jet has the advantage that it is readily moved to the location of interest and removes a large amount of heat. It has been widely used in such industrial systems as high-temperature gas turbines, paper drying, glass manufacturing, and high-density electronic equipment. The impinging jet used in these systems is air. Over the past 30 years, impingement cooling heat transfer has been extensively studied. Good review articles are available (Martin, 1977; Becko, 1976). The impinging flow structure (Donaldson and Snedeker, 1971a, 1971b), the local heat transfer, and the correlations of average Nusselt number in terms of relevant parameters have been well studied (Gardon and Cobonpue, 1963; Gardon and Akfirat, 1966; Korger and Krizek, 1965; Zumbrunnen et al., 1989). However, the impingement cooling studied in the past was on a flat plate. The situation of impingement cooling over a curved surface may frequently be encountered. However, the studies of impingement cooling on a curved surface are rela­tively few. Chupp et al. (1969) studied the impingement cooling heat transfer for an array of round jets impinging on a concave surface. The geometric configuration studied is very similar to the case for cooling of the leading edge of a gas turbine airfoil. They measure the local Nusselt number and correlate the av­erage Nusselt number in terms of the Reynolds number, the nozzle-to-plate spacing, and some nondimensional parameters of geometry. However, the local heat transfer obtained is ac­tually an average over a relatively large space. A similar ge­ometry is also studied by Metzger et al. (1969,1972) and Hrycak (1978, 1981). Tabakoff and Clevenger (1972) study three dif­ferent configurations of impinging jets on a concave surface: the single slot jet, the one-dimensional row of round jets, and the two-dimensional array of jets. Both the local and the av­erage Nusselt number are determined. However, the local heat transfer Nusselt number obtained is again an average over a relatively large space. A few correlations of average Nusselt numbers for slot jet impingement cooling over a concave or a

An Experimental Study of Entrainment Effects on the Heat Transfer From a Flat Surface to a Heated Circular Impinging Jet

Abstract: This paper reports on a study to investigate the effect of ambient air entrainment into a heated impinging jet on the heat transfer from a flat surface. It provides a well-characterized jet by using a long circular pipe to obtain fully developed pipe flow for the jet and a uniform heat flux surface thermal boundary condition by electrically heating a vacuum-deposited gold coating. The surface temperature distribution is measured using a liquid crystal.

Convective Heat Transfer by Impingement of Circular Liquid Jets

Abstract: The impingement of circular, liquid jets provides a convenient method of cooling surfaces. Here, jet impingement cooling of uniformly heated surfaces is investigated analytically and experimentally for stable, unsubmerged, uniform velocity laminar jets in the absence of phase change. Analytical and numerical predictions are developed for a laminar radial film flow. Experiments using undisturbed laminar jets were performed to determine local Nusselt numbers from the stagnation point to radii of up to 40 diameters. Turbulent transition in the film flow is observed experimentally at a certain radius. Beyond this transition radius, a separate turbulent analysis is constructed. Integral method results are compared to numerical results, and Prandtl number effects are investigated. The predictions are found to agree well with the measurements for both laminar and turbulent flow. Predictive formulae are recommended for the entire range of radii.

Development of a Flow Boiling Map for Subcooled and Saturated Flow Boiling of Different Fluids Inside Circular Tubes

Abstract: The thermal behavior of a flow boiling system is represented by a flow boiling map to illustrate visually the relationships among various system parameter. An earlier flow boiling map by Collier (1981) does not include the effect of mass flux and is specific to water at low pressures. For other fluids, significant departures from the parametric trends displayed in Collier's map have been reported in the literature (e.g, Kandlikar). In the present paper, a new flow boiling map is developed to depict the relationships among the heat transfer coefficient, quality, heat flux, and mass flux for different fluids in the subcooled and the saturated flow boiling regions. The trends observed in the experimental data and correlations for water and refrigerants are used in deriving the present map. The particular areas where further investigation is needed to validate the trends are also indicated. In the subcooled investigation is needed to validate the trends are also indicated. In the subcooled boiling region, h{sub TP}/h{sub lo} is plotted against x with Bo as a parameter, while in the saturated boiling region, h{sub TP}/h{sub lo} is plotted against x with {rho}{sub l}/{rho}{sub g} and a modified boiling number Bo* as parameters. It is hopedmore » that the map would prove to be helpful in explaining the role of different heat transfer mechanisms in flow boiling of different fluids.« less

Bubble Dynamics in Boiling Under High Heat Flux Pulse Heating

Abstract: A new theoretical model of bubble behavior in boiling water under high heat flux pulse is presented. The essence of the model is nucleation in the superheated liquid followed by instantaneous formation of a vapor film, rapid bubble growth due to the pressure impulse, and cavitation bubble collapse. To check the model, boiling of methanol under 5 {approximately} 50 MW m{sup {minus}2} heat flux pulse using a small thin film heater has been experimentally investigated. When the heat flux was relatively low ( 20 MW m{sup {minus}2}), many small bubbles nucleated and combined into a vapor film. The bubble behavior in the latter case is explained well by the model.

Numerical simulation of thermal transport associated with a continuously moving flat sheet in materials processing

Abstract: The thermal transport that arises due to the continuous motion of a heated plate or sheet in manufacturing processes such as hot rolling, extrusion, continuous casting, and drawing is numerically investigated. The resulting temperature distribution in the solid is influenced by the associated flow in the ambient fluid, which is taken as stationary far from this moving surface, and is of particular interest in this work. A numerical study is carried out, assuming a two-dimensional, steady circumstance with laminar flow in the fluid. The full governing equations, including buoyancy effects, are solved, employing finite-difference techniques. The effect of various governing parameters, such as the Peclet number, Pe, the mixed convection parameter, Gr/Re{sup 2}, and the conductivity parameter, K{sub f}/K{sub s}, which determine the temperature and flow fluids, is studied in detail. Also, the effect of the boundary conditions, particularly at the location of the emergence of the plate, on the downstream thermal transport is investigated. The penetration of the conductive effects, upstream of the point of emergence, is found to be significant. The effect of buoyancy is found to be more prominent when the plate is moving vertically upward than when it is moving horizontally. The appropriate boundary conditions andmore » their imposition in the numerical scheme are discussed for a variety of practical circumstances.« less

Fractal Network Model for Contact Conductance

Abstract: The topography of rough surfaces strongly influences the conduction of heat and electricity between two surfaces in contact. Roughness measurements on a variety of surfaces have shown that their structure follows a fractal geometry whereby similar images of the surface appear under repeated magnification. Such a structure is characterized by the fractal dimension D, which lies between 2 and 3 for a surface and between 1 and 2 for a surface profile. This paper uses the fractal characterization of surface roughness to develop a new network model for analyzing heat conduction between two contacting rough surfaces. The analysis yields the simple result that the contact conductance h and the real area of contact A{sub t} are related as h {approximately} A{sub t}{sup D/2} where D is the fractal dimension of the surface profile. Contact mechanics of fractal surfaces has shown that A{sub t} varies with the load F as A{sub t} {approximately} F{sup {eta}} where {eta} ranges from 1 to 1.33 depending on the value of D. This proves that the ocnductance and load are related as h {approximately} F{sup {eta}D/2} and resolves the anomaly in previous investigations, which theoretically and experimentally obtained different values for the load exponent. Themore » analytical results agreed well with previous experiments although there is a tendency for overprediction.« less

Nongray Radiative Gas Analyses Using the S-N Discrete Ordinates Method

Abstract: The S-N discrete ordinates method is applied to analyze radiative heat transfer in nongray gases. Spectral correlation between the terms in the equation of transfer is considered for black or nearly nonreflecting walls. Formulations to apply the S-N method using a narrow-band or the exponential wide-band model are presented. The net radiative wall heat fluxes and the radiative source distributions are obtained for uniform, parabolic, and boundary layer-type temperature profiles, as well as for a parabolic concentration profile. The narrow- and wide-band nongray solutions are compared with gray-band approximations using the same band models. The computational speed of the gray-band approximation is obtained at the expense of accuracy in the internal fluxes and radiative source distributions. The wall radiative flux predictions by the gray-band approximation are satisfactory.

Non-Darcy Mixed Convection Along a Vertical Wall in a Saturated Porous Medium

Abstract: In most of the previous studies of either natural or mixed convection, the boundary-layer formulation of Darcy's law and the energy equation were used. However, the inertial effect is expected to become very significant when the pore Reynolds number is large. This is especially true for the case of either the high Rayleigh number regime or for high-porosity media. In spite of its importance in many applications, the non-Darcy flow effect has not received much attention. In this note, non-Darcy flow effects, which include the inertial and thermal dispersion effects, are closely examined. Steady-state non-Darcy convection, in the form of natural, mixed, and forced convection, is considered for a heated vertical surface embedded in a saturated porous medium.

A Numerical Study of Developing Free Convection Between Isothermal Vertical Plates

Abstract: Steady two-dimensional laminar free convection between isothermal vertical plates including entrance flow effects has been numerically investigated. The full elliptic forms of the Navier-Stokes and energy equations are solved using novel inlet flow boundary conditions. Results are presented for Prandtl number Pr = 0.7, Grashof number range 50 {le} Gr{sub b} {le} 5 {times} 10{sup 4}, and channel aspect ratios of L/b = 10, 17, 24. New phenomena, such as inlet flow separation, have been observed. The results cast doubt on the validity of previous elliptic solutions. Comparisons with the approximate boundary-layer results show that a full elliptic solution is necessary to get accurate local quantities near the channel entrance.

A Model for Correlating Flow Boiling Heat Transfer in Augmented Tubes and Compact Evaporators

Abstract: The additive model for the convective and nucleate boiling components originally suggested by Bergles and Rohsenow (1964) for subcooled and low-quality regions was employed in the Kandlikar correlation (1990a) for flow boiling in smooth tubes. It is now extended to augmented tubes and compact evaporators. Two separate factors are introduced in the convective boiling and the nucleate boiling terms to account for the augmentation effects due to the respective mechanisms. The fin efficiency effects in the compact evaporator geometry are included through a reduction in the nucleate boiling component over the fins due to a lower fin surface temperature. The agreement between the model predictions and the data reported in the literature is within the uncertainty bounds of the experimental measurements.

A comparative study of methods for computing the diffuse radiation viewfactors for complex structures

Abstract: Several different numerical methods for calculating diffuse radiation viewfactors are described. Each is applied to a range of surface configurations, from almost completely unobstructed to a dense set of intersecting surfaces. The speed, accuracy, and unique characteristics are discussed in order to define optimal methods for different surface geometries.

Experimental and Numerical Analysis of Low-Temperature Heat Pipes With Multiple Heat Sources

Abstract: A numerical analysis and experimental verification of the effects of heat load distribution on the vapor temperature, wall temperature, and the heat transport capacity for heat pipes with multiple heat sources is presented. A numerical solution of the elliptic conjugate mass, momentum and energy equations in conjunction with the thermodynamic equilibrium relations and appropriate boundary conditions for the vapor region, wick structure, and the heat pipe wall are given. The experimental testing of a copper-water heat pipe with multiple heat sources was also made showing excellent agreement with the numerical results. An optimization of the heat distribution for such heat pipes was performed and it was concluded that by redistribution of the heat load, the heat capacity can be increased.

Heat Transfer Characteristics of Porous Radiant Burners

Abstract: This paper reports a numerical study of the heat transfer characteristics of porous radiant burners, which have significant advantages over conventional burners. The heat transfer characteristics are investigated using a one-dimensional conduction, convection, and radiation model. The combustion phenomenon is modeled as spatially dependent heat generation. Nonlocal thermal equilibrium between the gas and solid phases is accounted for by using separate energy equations for the two phases. The solid matrix is assumed to emit, absorb, and scatter radiant energy. The spherical harmonics approximation is used to solve the radiative transfer equation. The coupled energy equations and the radiative transfer equations are solved using a numerical iterative procedure. The effects of the various factors on the performance of porous radiant burners rae determined. It is revealed that for a given rate of heat generation, large optical thicknesses and high heat transfer coefficients between the solid and gas phases are desirable for maximizing radiant output. Also, low solid thermal conductivities, scattering albedos and flow velocities, and high inlet environment reflectivities produced high radiant output.

An Experimental Study of Convective Heat Transfer in Radially Rotating Rectangular Ducts

Abstract: The paper presents an experimental study of convective heat transfer in radially rotating isothermal rectangular ducts with various height and width aspect ratios. The convective heat transfer is affected by secondary flows resulting from Coriolis force and the buoyancy flow, which is in turn due to the centrifugal force in the duct. The growth and strength of the secondary flow depend on the rotational Rayleigh number. The aspect ratio of the duct may affect the secondary flow and the buoyancy flow, and therefore is also a critical parameter in the heat transfer mechanism. In the present work the effects of the main flow, the rotational speed, and the aspect ratio {gamma} on heat transfer are subjects of major interest. Ducts of aspect ratios {gamma} = 5, 2, 1, 0.5, and 0.2 at rotational speed up to 3,000 rpm are studied. The main flow Reynolds number ranges from 700 to 20,000 to cover the laminar, transitional, and turbulent flow regimes in the duct flow. Thest data and discussion are presented.

Numerical predictions of local entropy generation in an impinging jet

Abstract: Local entropy generation rates related to viscous dissipation and heat transfer across finite temperature differences can be calculated for isotropic and Newtonian fluids from the temperature and velocity fields in a thermal process. This study consisted of the development of a numerical procedure for the prediction of local entropy generation rates and the application of that procedure to convective heat transfer associated with a fluid jet impinging on a heated wall. The procedure involved expanding an existing computation fluid dynamics computer code to include the numerical calculation of local entropy generation. The modified code was benchmarked against analytical solutions and was then used to simulate a cold fluid jet impinging on a hot wall. The results show that the calculation of local entropy generation is feasible and can provide useful information.

Correlation of thermal conductivities of unidirectional fibrous composites using local fractal techniques

Abstract: The arrangement of fibers strongly influences heat conduction in a composite. Traditional approaches using unit cells to describe the fiber arrangements work well in the case of ordered arrays, but are not useful in the context of disordered arrays, which have been analyzed in the literature by statistical means. This work presents a unified treatment using the tool of local fractal dimensions (although, strictly speaking, a composite cross section may not be an exact fractal) to reduce the geometric complexity of the relative fiber arrangement in the composite. The local fractal dimensions of a fibrous composite cross section are the fractal dimensions that it exhibits over a certain small range of length scales. A generalized unit cell is constructed based on the fiber volume fraction and local fractal dimensions along directions parallel and transverse to the heat flow direction. The thermal model resulting from a simplified analysis of this unit cell is shown to be very effective in predicting the conductivities of composites with both ordered as well as disordered arrangement of fibers. For the case of square packing arrays, the theoretical result of the present analysis is identical to that of Springer and Tsai.

Convective heat and mass transfer in the stagnation region of a laminar planar jet impinging on a moving surface

Abstract: Manufacturing processes frequently employ impinging jets to cool or dry a material. Materials are often in motion since many manufacturing processes are designed to produce large quantities of a product. In some cases, the surface velocity can exceed or be comparable to the jet impingement velocity. In this study, the stagnation region of a laminar, planar jet is considered where surface motion is directed perpendicular to the jet plane. A similarity solution to the Navier-Stokes equations is formulated to determine the flow velocity in the stagnation region. Heat and mass transfer distributions are determined from numerical solutions to the conservation equations for energy and species, where velocity components are calculated from the similarity solution. Restrictions regarding the use of heat and mass transfer correlations, which are commonly developed with experimental apparatuses where the impingement surface is stationary, are provided.

Infrared Radiation Statistics of Nonluminous Turbulent Diffusion Flames

Abstract: Mixture fraction and radiation statistics were studied for radiation paths through turbulent carbon monoxide/hydrogen diffusion flames burning in still air. Measurements included Mie scattering for mixture fraction statistics and fast-response infrared spectroscopy for radiation statistics. Measured mixture fraction statistics also were used to predict radiation statistics based on stochastic time series methods, the laminar flamelet approximation, and a narrow-band radiation model. Measured intensities of radiation fluctuations were in the range 10-40%, which causes mean radiation levels to be 1.1-4.2 times larger than estimates based on mean scalar properties in the flames. In contrast, stochastic predictions of mean and fluctuating radiation properties were generally in excellent agreement with measurements. An exception was the temporal integral scales of radiation fluctuations, where differential diffusion errors of the Mie scattering measurements were identified as the source of the discrepancies.

Convection in magnetic fluids with internal heat generation

Abstract: The effect of a uniform distribution of heat source on the onset of stationary convection is a horizontal Boussinesq magnetic fluid layer bounded by isothermal nonmagnetic boundaries is investigated. Solutions are obtained using a higher order Galerkin expansion technique, considering different isothermal boundary combinations (rigid-rigid, rigid-free, and free-free). It is found that the effect of internal magnetic number, due to a heat source , is to make the system more unstable. The results obtained, in the limiting cases, compare well with the existing literature.

Natural convection in a vertical enclosure filled with anisotropic porous media

Abstract: Test data are correlated in Fig. 2 in the form of a Nu versus Ra graph with the diameter of the heating surface as the char­ acteristic length. Included for comparison are the empirical formulas recommended by McAdams (1955) for a heated hor­ izontal plate facing upward. Fixing the exponents based on the McAdams recommendations, one finds the coefficients that best fit the data of the composite surface. This yields: Nu = 1.125 Ra1/4 for 10 4

Inverse heat conduction applied to the measurement of heat transfer coefficient on a cylinder: Comparison between an analytical and a boundary element technique

Abstract: A new method using either an analytical or a boundary element inverse technique, is developed for measurement of local heat transfer coefficients. The direct model calculates the temperature field inside a cylindrical pipe. This is submitted to a given heat transfer coefficient angular profile on its outer radius and on an uniform temperature on its inner radius. Experimental temperature measurements inside the cylinder are processed by two techniques. Their results are very close and coherent with those of other authors. Variation of the cylinder conductivity with temperature, implemented by the boundary element technique, seems to show that the averaging of its value yields a regularization effect.

Regional heat transfer in two-pass and three-pass passages with 180-deg sharp turns

Abstract: The heat transfer distributions for flow passing through two-pass (one-turn) and three-pass (two-turn) passages with 180-deg sharp turns are studied by using the analogous naphthalene mass transfer technique. Both passages have square cross section and length-to-height ratio of 8. The passage surface, including top wall, side walls, and partition walls, is divided into 26 segments for the two-pass passage and 40 segments for the three-pass passage. Mass transfer results are presented for each segment along with regional and overall averages. The very nonuniform mass transfer coefficients measured around a sharp 180-deg turn exhibit the effects of flow separation, reattachment, and impingement, in addition to secondary flows. Results for the three-pass passage indicate that heat transfer characteristics around the second turn are virtually the same as those around the first turn. This may imply that, in a multiple-pass passage, heat transfer at the first turn has already reached the thermally developed (periodic) condition. Over the entire two-pass passage, the heat transfer enhancement induced by the single-turn is about 45 to 65% of the fully developed values in a straight channel. Such as heat transfer enhancement decreases with an increase in Reynolds number. In addition, overall heat transfer of three-pass passage ismore » approximately 15% higher than that of the two-pass one. This 15% increase appears to be Reynolds number independent. The pressure loss induced by the sharp turns is found to be very significant. Within the present testing range, the pressure loss coefficient for both passages is Reynolds number dependent.« less

Influence of high mainstream turbulence on leading edge heat transfer

Abstract: The influence of high mainstream turbulence on leading edge heat transfer was studied. High mainstream turbulence was produced by a bar grid (Tu = 3.3–5.1 percent), passive grid (Tu = 7.6–9.7 percent), and jet grid (Tu = 12.9–15.2 percent). Experiments were performed using a blunt body with a semicylinder leading edge and flat sidewalls. The mainstream Reynolds numbers based on leading edge diameter were 25,000, 40,000, and 100,000. Spanwise and streamwise distributions of local heat transfer coefficients on the leading edge and flat sidewall were obtained. The results indicate that the leading edge heat transfer increases significantly with increasing mainstream turbulence intensity, but the effect diminishes at the end of the flat sidewall because of turbulence decay. Stagnation point heat transfer results for high turbulence intensity flows agree with the Lowery and Vachon correlation, but the overall heat transfer results for the leading edge quarter-cylinder region are higher than their overall correlation for the entire circular cylinder region. High mainstream turbulence tends not to shift the location of the separation-reattachment region. The reattachment heat transfer results are about the same regardless of mainstream turbulence levels and are much higher than the turbulent flat plate correlation.

Thermal Aspects of Grinding: Heat Transfer to Workpiece, Wheel, and Fluid

Abstract: A model of heat transfer in grinding has been developed that considers heat removed from the grinding zone by the workpiece, abrasive grains, and grinding fluid. This model eliminates the need to specify the fraction of the total grinding power that enters the workpiece, or the convection coefficient due to the grinding fluid. The dependence of the workpiece temperature on the various grinding parameters has been explored.