Publications by Raffaele Luca Amalfi

Hybrid Two-Phase Cooling Technology For Next-Generation Servers: Thermal Performance Analysis

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo

This paper advances the work presented at ITHERM 2020 where a novel passive two-phase technology was introduced for more efficient cooling of datacenters compared to air-based cooling solutions (e.g. In-Room, In-Row, etc.). The proposed hybrid two-phase co ...

IEEE2021

Operational Map And Thermal Performance Of A Thermosyphon Cooling System For Compact Servers

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo

This paper advances the state-of-the-art in novel passive two-phase systems for more efficient cooling of datacenters and telecom central offices compared to the traditional air-based cooling solutions (e.g. aisle-based containment systems). The proposed p ...

AMER SOC MECHANICAL ENGINEERS2021

Compact Thermosyphon Cooling System For High Heat Flux Servers: Validation Of Thermosyphon Simulation Code Considering New Test Data

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo

Passive, gravity-driven thermosyphons represent a stepchange in technology towards the goal of greatly reducing PUE (Power Usage Effectiveness) of datacenters by replacing energy hungry fans of air-cooling approach with a highly-reliable solution able to d ...

AMER SOC MECHANICAL ENGINEERS2021

Novel pulsating heat pipe for high density power data centres: performance and flow regime analysis

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo

With the advancement of technologies such as Artificial Intelligence and 5G telecommunications, where computational rate is constantly pushing its limits, highly efficient and reliable cooling devices are starting to become an overly critical factor. Not o ...

IEEE2021

Design Of Passive Two-Phase Thermosyphons For Server Cooling

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo

The main objective of this paper is to utilize an improved version of the simulator presented at InterPACK 2017 to design a thermosyphon system for energy-efficient heat removal from 2-U servers used in high-power datacenters. Currently, between 25% and 45 ...

AMER SOC MECHANICAL ENGINEERS2020

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

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Chiara Falsetti

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 ...

IEEE2019

Numerical Simulations of Pulsating Heat Pipes, Part 1: Modeling

John Richard Thome, Jackson Braz Marcinichen, Brian Paul D'Entremont, Raffaele Luca Amalfi, Filippo Cataldo, Philippe Aubin

The pulsating nature of a closed loop pulsating heat pipe (CLPHP) makes the prediction of its thermal-hydraulic performance extremely challenging. Unfortunately, the design of CLPHPs is still quite an empirical process, requiring testing of many prototypes ...

IEEE2019

Numerical Simulations of Pulsating Heat Pipes, Part 2: Comparison to Experimental Data

John Richard Thome, Jackson Braz Marcinichen, Raffaele Luca Amalfi, Filippo Cataldo, Philippe Aubin

Due to the local pulsating/transient nature and complex thermal-hydraulic coupling of a closed loop pulsating heat pipe (CLPHP), there is a need to develop an effective simulation code capable to design and predict the local and overall thermal performance ...

IEEE2019

Role of a Liquid Accumulator in a Passive Two-Phase Liquid Cooling System for Electronics: Experimental Analysis

John Richard Thome, Jackson Braz Marcinichen, Nicolas Lamaison, Raffaele Luca Amalfi

2018

Thermal Interface Material Enablement of Off-Board Two-Phase Cooling

John Richard Thome, Raffaele Luca Amalfi

Two-phase, refrigerant-based cooling offers significant promise for increasing heat densities and energy efficiencies of electronic components. One barrier to wide spread adoption of two-phase cooling solutions is preserving product features deemed essenti ...

IEEE2018

Two-Phase Flow Simulations within Plate Heat Exchangers

John Richard Thome, Raffaele Luca Amalfi

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 ...

IEEE2018

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

John Richard Thome, Chin Lee Ong, Jackson Braz Marcinichen, Nicolas Lamaison, Raffaele Luca Amalfi

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 ...

Amer Soc Mechanical Engineers2017

Role Of A Liquid Accumulator In A Passive Two-Phase Liquid Cooling System For Electronics: Experimental Analysis

John Richard Thome, Jackson Braz Marcinichen, Nicolas Lamaison, Raffaele Luca Amalfi

Gravity-driven two-phase liquid cooling systems using flow boiling within micro-scale evaporators are becoming a game changing solution for electronics cooling. The optimization of the system's filling ratio can however become a challenging problem for a s ...

Amer Soc Mechanical Engineers2017

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

John Richard Thome, Raffaele Luca Amalfi

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 ...

Pergamon-Elsevier Science Ltd2016

High resolution local heat transfer and pressure drop infrared measurements of two-phase flow of R245fa within a compact plate heat exchanger

John Richard Thome, Raffaele Luca Amalfi

An experimental study is presented to characterize two-phase thermal and hydraulic performance of a prototype corrugated plate heat exchanger with small pressing depth. In particular, upward flow boiling of low pressure refrigerant R245fa was investigated ...

Pergamon-Elsevier Science Ltd2016

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

John Richard Thome, Raffaele Luca Amalfi

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 ...

Pergamon-Elsevier Science Ltd2016

Flow boiling and frictional pressure gradients in plate heat exchangers. Part 2: Comparison of literature methods to database and new prediction methods

John Richard Thome, Farzad Vakili Farahani, Raffaele Luca Amalfi

In the second part of this study a sensitivity analysis on the prediction methods is performed to consider the effect of plate geometry on thermal hydraulic performance and an extensive comparison of all the two-phase pressure drop and flow boiling heat tr ...

Elsevier Sci Ltd2016

Boiling heat transfer and two-phase pressure drops within compact plate heat exchangers: Experiments and flow visualizations

John Richard Thome, Raffaele Luca Amalfi

Infrared (IR) thermography was used to measure the local heat transfer coefficients within two plate heat exchanger geometries. The chevron patterns were machined into polycarbonate and IR transparent calcium fluoride plates, both of which were electricall ...

Pergamon-Elsevier Science Ltd2016

Flow boiling and frictional pressure gradients in plate heat exchangers. Part 1: Review and experimental database

John Richard Thome, Farzad Vakili Farahani, Raffaele Luca Amalfi

This two-part paper presents an overview of evaporation heat transfer mechanisms, a review of the experimental and prediction methods and a creation of a consolidated multi-lab database of 3601 data points and provides a detailed comparison of all the pred ...

Elsevier Sci Ltd2016

Two-Phase Heat Transfer Mechanisms within Plate Heat Exchangers : Experiments, Modeling and Simulations

Raffaele Luca Amalfi

Plate heat exchangers are adopted in many domestic and industrial applications, such as ventilation, air conditioning, evaporation or condensation process, heat pumps and cooling of hydrodynamic circuits in engines. In the present thesis, an extensive expe ...

EPFL2016