Publications related to Intermittent dewetting and dryout of annular flows

Extension of GeN-Foam to departure from nucleate boiling prediction and validation against the OECD/NRC PSBT benchmark

Alessandro Scolaro, Carlo Fiorina, Hao Qin, Yuhang Niu

The prediction of departure from nucleate boiling (DNB) has always been a crucial aspect of thermal-hydraulic codes for the analysis of Light Water Reactors. In this paper, GeN-Foam, a multi-physics code developed based on OpenFOAM, has been enhanced to in ...

Elsevier Science Sa2023

Heat transfer of uncoated and nanostructure coated commercially micro-enhanced refrigeration tubes under pool boiling conditions

John Richard Thome

The heat transfer performance of commercially produced micro-enhanced tubes with and without a nanocoating was investigated under pool boiling of saturated refrigerant. These multiscale enhancements were on the outside of 19 mm horizontal copper tubes heat ...

Pergamon-Elsevier Science Ltd2023

Experimental study of the hydrodynamic and thermal performances of ventilated wall structures

Mohammad Rahiminejad, Dolaana Khovalyg

The presence of a ventilated air gap behind the external cladding in a building envelope is known to have a tangible contribution to the overall performance of the wall assembly. In the present study, the hydrodynamic and thermal performances of ventilated ...

2023

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

John Richard Thome

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 ...

Pergamon-Elsevier Science Ltd2023

Extension of GeN-Foam to modeling of boiling water and validation against the OECD/NRC PSBT benchmark

Stefan Radman, Carlo Fiorina, Ran Zhang, Hao Qin

The OpenFOAM-based GeN-Foam solver has recently been extended to allow simulating water boiling based on a porous-medium approach. This paper describes such extension and preliminarily validates it based on the OECD/NRC PSBT benchmark. Three benchmark exer ...

ELSEVIER SCIENCE SA2023

Near-junction microfluidic cooling for high power-density GaN-on-Si electronics: A wafer, device, packaging, and system-level investigation

Remco Franciscus Peter van Erp

Electrification of the energy section, from generation to end-use, plays an essential role in reducing global CO2 emission. Innovations in power electronics are required to increase conversion efficiency and power density. Gallium nitride (GaN) transistors ...

EPFL2022

A parametric study on pool boiling heat transfer and critical heat flux on structured surfaces with artificial cavities

Luis Guillermo Villanueva Torrijo, Ahmad Reza Motezakker

Emerging applications in new generation electronic devices require effective heat removal and thermal man-agement. In this regard, boiling is a phase change phenomenon capable of dissipating a large amount of heat compared to the sensible heat. In this stu ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Flow Boiling of Carbon Dioxide at Different Channel Orientations for the Thermal Management of Future Detector Technologies at the High-Luminosity Large Hadron Collider at CERN

David Schmid

The global warming potential (GWP) of working fluids in thermodynamic cycles and their environmental impact have been gaining considerable attention within the recent years. The global objectives on climate protection are becoming increasingly ambitious, w ...

EPFL2022

Heat recovery potential from ventilated passive and active facades

Mohammad Rahiminejad, Dolaana Khovalyg

A ventilated air-space behind external claddings can potentially affect the thermal performance of the entire building structure. In particular, in the Building Integrated Photovoltaic (BIPV) facades, ventilated cavities are typically present between the P ...

TU Delft OPEN2022

Heat transfer of flow boiling carbon dioxide in vertical upward direction

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

Heat transfer measurements of flow boiling Carbon Dioxide (CO2) in vertical upward direction have been carried out with a dedicated test facility at the European Organization for Nuclear Research (CERN). The experiments have been conducted in a vertical up ...

2022

Simulation and experimental validation of pulsating heat pipes

John Richard Thome, Jackson Braz Marcinichen, Filippo Cataldo, Philippe Aubin

The one-dimensional transient numerical code of JJ Cooling Innovation has been significantly improved to simulate the thermal/hydraulic performance of pulsating heat pipes (PHPs). Using a mechanistic approach, the liquid slug and vapor plug flows and their ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Fundamental study on microlayer dynamics in nucleate boiling

Lubomír Bures

Dynamics of nucleate boiling are strongly affected by the formation and behaviour of the microlayer, a layer of liquid underneath growing bubbles. As a result of its minute thickness, very high heat fluxes occur within the microlayer and its evaporation co ...

EPFL2021

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

John Richard Thome

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 ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Thermal management of components for high energy physics experiments and space applications

Timothée Robert Sophus Frei

High-energy physics (HEP) experiments and space missions share a common challenge: thermal management in harsh environments. The severe constraints in both fields make cooling of electronic components a major design concern. This thesis aims to develop hig ...

EPFL2021

Experimental investigation and analysis of sequential jet impingement concepts for enhanced turbine cooling

Michele Gaffuri

With the future decarbonization of the electricity production, gas turbines will be an important tool for the stabilization of the electricity grid by meeting the peak of energy demand using zero-carbon fuels like synthetic gas and hydrogen. The combustion ...

EPFL2021

Heat Transfer Enhancement in a Double Sequential Impingement Channel

Peter Ott, Michele Gaffuri

Sequential impingement channels can reduce the adverse effect of crossflow in narrow impingement channels, as well as increase the cooling efficiency. In this work, sequential impingement channels are experimentally investigated using the transient liquid ...

2021

A Pixel Design of a Branching Ultra-Highspeed Image Sensor

Edoardo Charbon

A burst image sensor named Hanabi, meaning fireworks in Japanese, includes a branching CCD and multiple CMOS readout circuits. The sensor is backside-illuminated with a light/charge guide pipe to minimize the temporal resolution by suppressing the horizont ...

2021

Thermomechanical behavior of underground energy infrastructures

Jacopo Zannin

The employment of geostructures as structural supports and as heat exchangers represent an effective, renewable and sustainable way to satisfy thermal needs of the built environment. The structural support of conventional geotechnical structures is coupled ...

EPFL2020

Impact of air-flow on thermal performance of air-spaces behind cladding (ASHRAE 1759-TRP)

Mohammad Rahiminejad, Dolaana Khovalyg

The project ASHRAE 1759-RP addresses the impact of the ventilated cavity behind external claddings on the thermal performance of the wall structure by defining “effective thermal resistance” of air gaps based on the linearized network of thermal resistance ...

ASHRAE2020

Graph-based regularization of inverse problems in imaging

Mattia Rossi

As of today, the extension of the human visual capabilities to machines remains both a cornerstone and an open challenge in the attempt to develop intelligent systems. On the one hand, the development of more and more sophisticated imaging devices, capable ...

EPFL2020