Imperial College London


Faculty of EngineeringDepartment of Chemical Engineering

Professor of Clean Energy Technologies



+44 (0)20 7594 1601c.markides Website




404ACE ExtensionSouth Kensington Campus






BibTex format

author = {Sapin, P and Taleb, A and Barfuß, C and White, AJ and Fabris, D and Markides, CN},
title = {Thermodynamic Losses in a Gas Spring: Comparison of Experimental and Numerical Results},
url = {},

RIS format (EndNote, RefMan)

AB - Reciprocating-piston devices can be used as high-efficiencycompressors and/or expanders. With an optimal valve design andby carefully adjusting valve timing, pressure losses during intakeand exhaust can be largely reduced. The main loss mechanismin reciprocating devices is then the thermal irreversibility dueto the unsteady heat transfer between the compressed/expandedgas and the surrounding cylinder walls. In this paper, pressure,volume and temperature measurements in a piston-cylindercrankshaft driven gas spring are compared to numerical results.The experimental apparatus experiences mass leakage while theCFD code predicts heat transfer in an ideal closed gas spring.Comparison of experimental and numerical results allows one tobetter understand the loss mechanisms in play. Heat and masslosses in the experiment are decoupled and the system lossesare calculated over a range of frequencies. As expected, compressionand expansion approach adiabatic processes for higherfrequencies, resulting in higher efficiency. The objective of thisstudy is to observe and explain the discrepancies obtained betweenthe computational and experimental results and to proposefurther steps to improve the analysis of the loss mechanisms.
AU - Sapin,P
AU - Taleb,A
AU - Barfuß,C
AU - White,AJ
AU - Fabris,D
AU - Markides,CN
TI - Thermodynamic Losses in a Gas Spring: Comparison of Experimental and Numerical Results
UR -
ER -