Publications by John Richard Thome

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A new falling film heat transfer test facility has been built for the measurement of local heat transfer coefficients on a vertical array of horizontal tubes, including flow visualization capabilities, for use with refrigerants. Presently, the facility has ...

Intube evaporation tests for R-407C and R-407C/oil are reported for a microfin tube. The tests were run at a nominal inlet pressure of 6.45 bar (93.5psia) at mass velocities of 100, 200 and 300 kg/m2s (73581, 147162 and 220743 lb/h ft2) over nearly the entire vapor quality range. Pure R-407C performed similar to previous pure R-134a tests at the highest mass velocity, but lower for the other mass velocities, at similar operating conditions. Any amount of oil tended to decrease local R-407C micorfin heat tra

An extensive experimental study was undertaken to measure nucleate pool boiling heat transfer coefficients, local bundle boiling heat transfer coefficients, and two-phase bundle pressure drops for R134a and R236fa on one plain tube bundle configuration. Th ...

Micro particle shadow velocimetry (mu PSV) is performed in the present study for simultaneous velocity measurement and interface tracking in both liquid-liquid and gas-liquid two-phase flows through circular microchannels of 5001 mu m diameter. The back-li ...

Two-phase flow pattern data have been obtained experimentally for R-407C flowing inside 12 mm bore sight glasses, which were located at the outlets of 3 m long, plain bore copper tube heat transfer test sections. The tests covered nominal mass velocities of 100, 200 and 300 kg/m2s, vapor qualities from 5-95%, and a wide range of heat fluxes, all taken at a fixed inlet saturation pressure of 6.45 bar to the evaporator test section. The flow pattern data were compared to the newly developed two-phase frow pat

New enhanced boiling tubes from Wolverine Tube Inc. (Turbo-B5) and Wieland-Werke AG (Gewa-B5) were investigated using R-134a and R-236fa as test fluids. The tests were done at saturation temperatures of 5 and 15 degrees C, mass flow rates from 4 to 35 kg m ...

Boiling heat transfer in microchannels has been investigated extensively in the last two decades. However, most results from independent experimental studies display a substantial disagreement on the influence of the flow conditions and mechanisms on the h ...

This study considers the prediction of the degree of asymmetry in the circumferential distribution of the liquid film in the tube cross section of horizontal annular gas-liquid two-phase flow, endemic of the lower region of this flow regime near the strati ...

New saturated critical heat flux (CHF) data have been obtained experimentally in two different multi-microchannel heat sinks made in copper with three low pressure refrigerants (R134a, R236fa, R245fa). one of the test sections has 20 parallel rectangular c ...

The study considers algebraic turbulence modeling in adiabatic and evaporating annular two-phase flow, focusing in particular on momentum and heat transfer (so-called 'convective boiling') through the annular liquid film. In contrast with single-phase wall ...

This article investigates the effect of inlet orifices on saturated critical heat flux (CHF) in multi-microchannel heat sinks. Two different multi-microchannel heat sinks made in copper were tested with three low pressure refrigerants (R134a, R236fa, R245f ...

This two-part paper presents experimental work to characterize thermal and hydraulic performances of a compact plate heat exchanger. Upward single-phase heat transfer and pressure drop of low pressure, liquid refrigerants R245fa and R236fa was investigated ...

A summary of a comprehensive experimental study on flow boiling heat transfer is presented for five refrigerants (R134a, R123, R402A, R404A and R502) evaporating inside plain horizontal, copper tube test sections. The test data were obtained for both 12.00 mm and 10.92 mm diameters using hot water as the heating source. Besides confirming known trends in flow boiling heat transfer data as a function of test variables, it was also proven that the heat flux level at the dryout point at the top of the tube in

The present study focuses on an experimental investigation of two-phase flow boiling in a silicon multi-microchannel evaporator, which emulates a single layer of a 3D stacked computer chip. The micro-evaporator is comprised of 67 parallel channels, each ha ...

Nowadays, datacenters heat density dissipation follows an exponential increasing trend that is reaching the heat removal limits of the traditional air-cooling technology. Two-phase cooling implemented within a gravity-driven system represents a scalable an ...

Heat transfer coefficients for enhanced tubes are typically measured indirectly using the "Wilson plot" method to first characterize the thermal performance of the one side (heating or cooling supply) and then to obtain the heat transfer data for the enhan ...

An improved two-phase flow pattern map is proposed for evaporation in horizontal tubes. Based on new flow pattern data for three different refrigerants covering a wide range of mass velocities, vapor qualities and heat fluxes. The new flow pattern map includes the prediction of the onset of dryout at the top of the tube during evaporation inside horizontal tubes as a function of heat flux and flow parameters and is an extension to the flow pattern map model of Kattan et al.(5). The modifications proposed al

Saturated critical heat flux (CHF) is an important issue during flow boiling in mini and microchannels. To determine the best prediction method available in the literature, 2996 data points from 19 different laboratories have been collected since 1958. The ...

This paper presents a state-of-the-art review of two-phase flow and flow boiling across horizontal tube bundles. The review covers studies related to the dynamic aspects of two-phase flow on the shell side of staggered and in-line tube bundles for upward, ...

Flow patterns for adiabatic vertical downward air water flow in an 8.8 mm diameter channel have been studied. In particular, the influence of the inlet device, the flow history and the development length on the flow pattern have been investigated and assessed. Test results with two inlet devices (highly mixed and unmixed) indicate that the inlet device has a major influence on the flow pattern transitions. Furthermore, the transition boundaries between different flow regimes have been found to depend strong

John Richard Thome

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Falling Films on Arrays of Horizontal Tubes with R-134a, Part I: Boiling Heat Transfer Results for Four Types of Tubes

Intube Flow Boiling of R-407C and R-407C/Oil Mixtures. Part 1: Microfin Tube

Boiling on a Tube Bundle: Part II-Heat Transfer and Pressure Drop

Application of micro particle shadow velocimetry mu PSV to two-phase flows in microchannels

Prediction of Two-Phase Flow Patterns for Evaporation of Refrigerant R–407C Inside Horizontal Tubes.

Flow boiling data and prediction method for enhanced boiling tubes and tube bundles with R-134a and R-236fa including a comparison with falling film evaporation

A CFD study of the parameters influencing heat transfer in microchannel slug flow boiling

Liquid film circumferential asymmetry prediction in horizontal annular two-phase flow

Critical heat flux in multi-microchannel copper elements with low pressure refrigerants

Algebraic turbulence modeling in adiabatic and evaporating annular two-phase flow

Effect of Inlet Orifice on Saturated CHF and Flow Visualization in Multi-microchannel Heat Sinks

High resolution infrared measurements of single-phase flow of R245fa and R236fa within a compact plate heat exchanger, Part 1: Experimental setup and pressure drop results

Flow Boiling in Horizontal Tubes. Part 2; New Heat Transfer Data for Five Refrigerants

Two-Phase Flow Boiling in a Single Layer of Future High-Performance 3D Stacked Computer Chips

Two-Phase Mini-Thermosyphon For Cooling Of Datacenters: Experiments, Modeling And Simulations

Modified Wilson Plots for Enhanced Heat Transfer Experiments: Current Status and Future Perspectives

Development of a Diabatic Two-Phase Flow Pattern Map for Horizontal Flow Boiling

Status of prediction methods for critical heat fluxes in mini and microchannels

Two-Phase Flow and Heat Transfer across Horizontal Tube Bundles – A Review

Adiabatic vertical downward air-water flow pattern map: influence of inlet device, flow development length and hysteresis effects