Showing papers in "Experimental Thermal and Fluid Science in 1995"

TL;DR: In this paper, the development of thermal-hydraulic design tools for rectangular offset strip fin compact heat exchangers and the associated convection process are delineated, and existing empirical f and j data for actual cores are reanalyzed.

TL;DR: A review of vortex-induced heat transfer enhancement can be found in this article, where the theoretical basis for the method is discussed and both active and passive implementations are reviewed, and the aim of this survey is to critically review recent progress and to identify research needs in the area of vortexinduced heat exchanger enhancement.

TL;DR: The naphthalene sublimation method can be used to study mass and heat transfer with confidence for a variety of applications, but with certain restrictions as discussed by the authors, such as high-velocity flows.

TL;DR: In this paper, the combustion of liquid fuels within the porous inert media (PIM) of a radiant burner was examined, and various design configurations were tested using the following types of porous ceramics: magnesia-stabilized zirconia, silicon carbide, and yttrium-stantioned zircania.

TL;DR: In this paper, high flux evaporation from a steady meniscus formed in a 2 micron channel is modeled using the augmented Young-Laplace equation, and the heat flux is found to be a function of the long range van der Waals dispersion force which represents interfacial conditions between heptane and various substrates.

TL;DR: In this paper, the dynamic instability of two-phase flow associated with refrigerant R-11 in a uniformly heated horizontal in-tube boiling system was experimentally investigated, and the dependence of oscillation amplitude and period on system parameters was discussed, and boundaries of various oscillations are located on the steady-state characteristic curves.

TL;DR: In this paper, a sinusoidal wavy duct with constant wavelength λ/a, amplitude of the wavy wall a = 1.825 mm, duct width B = 150 mm, and duct length L = 400 mm for various duct heights s and a range of Reynolds numbers.

TL;DR: A flow regime map for determination of the boundary between forced and mixed convection in a horizontal circular straight tube with reentrant, square-edged, and bellmouth inlets under uniform wall heat flux boundary condition is developed in this article.

TL;DR: In this paper, a new theory of nucleate pool boiling based on turbulence in the boundary layer induced by bubble growth and departure is presented, which incorporates the effect of the static contact angle and explains the large spread of available experimental data.

TL;DR: In this article, the temperature distribution at the ribbed wall including both flanks of the ribs is measured by infrared thermography, and the complete temperature distribution along one geometric period is obtained by combining the resulting four images.

TL;DR: In this paper, the thermal contact conductance in a vacuum environment under low applied load was studied with square test plates (100 X 100 mm) made of aluminum alloy (A6061 and A5052).

TL;DR: In this article, an overview of the operating mechanisms of multi-louvered fin heat transfer surfaces is presented, and the performance of these surfaces is compared with that of other compact enhanced surfaces, and it is shown that they have the potential to compete in applications where overall size, weight and pumping power are important.

TL;DR: In this paper, flow visualization and LDV measurements are performed on laminar flow in a helical square duct with finite pitch, and the experimental observations are compared to results of numerical calculations employing the finite-volume method and assuming a fully developed flow.

TL;DR: In this paper, the void fraction was simulated by nonflow air-paraffin wax, airglass, air-wood, and air-Freon 113 systems, and the relative statistical error in void fraction measurement was minimized by taking into account the spacing between the ends of the two electrodes.

TL;DR: In this paper, the principles of the fluorescent paint technique for surface heat transfer measurement are presented, and the temperature sensitive paint is used to visualize and measure heat transfer in several typical shock-turbulent boundary layer interactions.

TL;DR: In this article, the authors developed an algorithm for deriving the transfer functions of the constant-temperature hot-wire anemometer of arbitrary complexity, and showed that the poles of the transfer function for electronic and velocity perturbations are identical regardless of the feedback amplifier and the nature and quantity of components used to model the bridge impedances.

TL;DR: In this paper, the spatial resolution of a parallel-wire probe is studied to evaluate the effect of finite wire spacing and wire length on the measurement of turbulence derivative quantities, and it is shown that the amount of spatial filtering predicted is highly sensitive to the spectral model for separation distances greater than 2-3 times the Kolmogorov length scale.

TL;DR: In this article, the authors investigated the heat and mass transfer characteristics for a falling liquid film evaporating into a gas stream and found that the latent heat transport connected with the vaporization of the liquid film plays an important role in the transfer processes.

TL;DR: In this paper, the authors describe available techniques and future developments for making measurements in high-enthalpy hypersonic test facilities, focusing on instrumentation for use with short-duration flows in free-piston shock tunnels.

TL;DR: In this paper, the mixing processes involving organized large-scale motion and chaotic small-scale motions across a sharp density interface were investigated experimentally via a pH-sensitive, laser-induced fluorescence technique in a water tank.

TL;DR: In this paper, three-wire heat flux sensors have been used in conjunction with a slip-ring apparatus for local heat transfer measurements on cylinders with length-to-diameter ratios varying from 3.80 to 6.50 under rotating condition with superimposed crossflow.

TL;DR: In this article, an introduction to the design, fabrication, and use of perforated plate heat exchangers is presented, focusing on the numerical solution of the heat exchange equations.

TL;DR: In this article, a guarded hot plate apparatus is employed to measure the thermal conductivity of equine cortical bone, and the resulting effective thermal conductivities are compared to a numerical solution of the experimental problem.

TL;DR: In this article, the tumble formation and decay mechanisms in a transparent four-valve engine were investigated by laser-Doppler velocimetry and analyzed by means of the tumble angular momentum and two nondimensional parameters, the tumble eccentricity and the shape factor in the tumble velocity profile.

TL;DR: In this article, an experimental investigation of a new convective rational heat transfer augmentation law in plate-fin heat exchanger surfaces is presented, characterized by Nu/Nusm ≥ ξ/ξsm by comparing channels with vortex promoters with similar smooth channels at equal Reynolds numbers.

TL;DR: In this article, a new technique based on the signature of turbulent spots on the heat flux at the wall is used to estimate the propagation rates of naturally occurring turbulent spots in a zero pressure gradient transitional boundary layer.

TL;DR: In this paper, an experimental and numerical investigation was conducted into channel flows with transverse vortex generators, periodically attached to one channel wall, and the oscillatory behavior of the flow was studied.

TL;DR: In this article, experiments in channel flow with pairs of rectangular winglets arranged periodically in both the streamwise and spanwise directions were conducted, and the results of the three components of the mean velocity and the long-time-averaged Reynolds stresses and the turbulent kinetic energy were presented.

TL;DR: In this article, the Nusselt number was determined from the isotherms at the wall in the boundary layer of a plate-fin heat exchanger using Holographic interferometry.

TL;DR: An optical technique for surface temperature measurement based on the fluorescent emission of rare earth ion-doped phosphors was demonstrated in an experiment with a heated cylinder in cross-flow as discussed by the authors, where a uniform heat flux was imposed by applying a constant voltage across the thin stainless steel cylinder surface to produce surface temperatures between 24°C and 55°C.