Publications by John Richard Thome

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The present study focused on the thermal hydraulic performance improvement of a CO2 gas cooler with the principal goal of reducing its volume, and consequently the necessary charge of the working fluid. To achieve this compactness, the leading methods for ...

Plate heat exchangers are widely adopted in many industrial applications, such as ventilation, air conditioning, heat transfer processes, heat pumps and cooling of hydrodynamic circuits in engines. They provide higher heat transfer performance, compactness ...

Passive two-phase, micro-channel cooling for thermal management of electronics represents an efficient and viable solution to augment conventional air-cooling systems with the potential for higher power dissipation densities, increased reliability, reduced ...

This paper presents a numerical model to predict laminar film condensation heat transfer in small channels of different internal geometries for miscible refrigerant-oil mixtures. The model includes the contributions of surface tension, axial shear stresses ...

Highlights • A “plug-and-play” microreaction system for high-temperature reactions (>500 °C). • Efficient thermal decoupling for using standard electrical/fluidic connections. • Automatic and accurate temperature control for calorimetric measurements. • A ...

A new method to predict the entrained liquid fraction in annular two-phase flow is presented. The underlying experimental database contains 2460 data points collected from 38 different literature studies for 8 different gas-liquid or vapor-liquid combinati ...

Transient modeling and regulation of a two-phase on-chip liquid pump cooling cycle is studied. The purpose is to cool down multiple micro-processors in parallel and a set of memories, DC/DC converters in series. The cycle will be incorporated in a blade/drawer of a rack as shown in Figure 1. The cooling system is composed of multiple on-chip micro-evaporators, a condenser, a liquid accumulator, a pump and all piping joining components. In order to take advantage of enhanced heat transfer and more uniform ch

The study is devoted to the modeling of microscale adiabatic gas-liquid annular two-phase flow. The turbulent diffusion of momentum in the annular liquid film is assumed to be governed by the conditions near the channel wall, in analogy with single-phase t ...

The paper presents a comprehensive review of fundamentals and engineering applications of CO2 flow boiling heat transfer, flow patterns and two-phase pressure drops in macro- and micro-channel evaporators. First, distinctions of macro- and micro-channels a ...

Two-phase liquid cooling of computer chips via microchannels etched directly on silicon dies is a potential long-term solution to enable continued integration of high-performance multiprocessors. Two-phase cooling refers to the heat removal via evaporation ...

The conversion to more environmentally friendly refrigerants is of prime importance for refrigeration and air-conditioning industries. A first option for the substitution of the fluids which use was banned could be natural refrigerants, such as CO2, or HFC ...

Multiscale surface structures offer the opportunity to combine the heat transfer enhancement provided by microscale structures with the dryout benefits provided by some nanostructures, which is particularly attractive for falling film evaporators, who have ...

This article is the second part of a study on flow boiling of R236fa and R245fa. This part presents the heat transfer coefficients obtained in a 12.7 mm silicon evaporator composed of 135 microchannels with 85 mu m wide and 560 mu m high channels separated ...

A comprehensive review of flow boiling characteristics and flow pattern visualization of refrigerant/lubricant oil mixtures is presented in this paper. First, various parameters influenced by the lubricant oil in convective boiling of refrigerants, such as ...

In the present paper, a closed-loop thermosyphon cooling system for power electronics has been developed and tested. The evaporator is a multi-microchannel heat sink designed for high heat fluxes. The power electronics module is emulated by four independen ...

This paper focuses on two-phase flow boiling of refrigerant R134a inside a copper multi-microchannel heat sink for microelectronic central processing unit cooling applications. The heat sink is composed of 100 parallel microchannels, 100 mu m wide, 680 mu ...

In the second article of the present two-part paper, upward single-phase heat transfer within a compact plate heat exchanger was investigated experimentally. The experimental setup, the data reduction technique and pressure drop results were presented in P ...

This paper describes the implementation of a 3D parallel and Cartesian level set (LS) method coupled with a volume of fluid (VOF) method into the commercial CFD code FLUENT for modeling the gas-liquid interface in bubbly flow. Both level set and volume of ...

The time-averaged two-phase flow heat transfer coefficients were determined with a very fine resolution based on infra-red (IR) temperature measurements conducted over a 1 cm(2) heated area of a multi-micro-, channel evaporator. This experimental investiga ...

Cooling of datacenters is estimated to have an annual electricity cost of 1.4 billion dollars in the United States and 3.6 billion dollars worldwide. Currently, refrigerated air is the most widely used means of cooling datacenter’s servers. Modern datacent ...

John Richard Thome

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Working fluid charge reduction. Part II: Supercritical CO2 gas cooler designed for light commercial appliances

Two-Phase Flow Simulations within Plate Heat Exchangers

Experimental Characterization of Different Condenser Technologies in a Passive Two-Phase Cooling System for Thermal Management of Electronics

Numerical modeling of the effects of oil on annular laminar film condensation in minichannels

Design and packaging of a highly integrated microreactor system for high-temperature on-board hydrogen production

Entrained liquid fraction prediction in adiabatic and evaporating annular two-phase flow

Transient Simulation of Two-Phase On-chip Liquid Pump Cycle for Processor's Cooling

Microscale Adiabatic Gas-Liquid Annular Two-Phase Flow: Analytical Model Description, Void Fraction, and Pressure Gradient Predictions

Flow boiling heat transfer and two-phase flow phenomena of CO2 in macro-and micro-channel evaporators: Fundamentals, applications and engineering design

STEAM: a fast compact thermal model for two-phase cooling of integrated circuits

CO2 and R410A: Two-phase flow visualizations and flow boiling measurements at medium (0.50) reduced pressure

Multiscale enhancement of refrigerant falling film boiling by combining commercially enhanced tubes with nanostructures

Two-phase flow of refrigerants in 85μm-wide multi-microchannels: Part II – Heat transfer with 35 local heaters

Flow boiling characteristics and flow pattern visualization of refrigerant/lubricant oil mixtures

Experimental evaluation of the thermal performances of a thermosyphon cooling system rejecting heat by natural and forced convection

Flow Boiling of R134a in a Multi-Microchannel Heat Sink with Hotspot Heaters for Energy-Efficient Microelectronic CPU Cooling Applications

High resolution infrared measurements of single-phase flow of R245fa and R236fa within a compact plate heat exchanger, Part 2: Heat transfer results

A Level Set Method Coupled With a Volume of Fluid Method for Modeling of Gas-Liquid Interface in Bubbly Flow

Fine-resolution two-phase flow heat transfer coefficient measurements of refrigerants in multi-microchannel evaporators

Efficiency Improvements of a Thermal Power Plant by Making Use of the Waste Heat of Large Datacenters using Two-Phase On-Chip Cooling