Optimal piston crevice study in a rapid compression machine

Oku Nyong, Robert Woolley, Simon Blakey, Ehsan Alborzi

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)


Multi-dimensional effects such as vortex generation and heat losses from the gas to the wall of the reactor chamber have been an issue to obtaining a reliable RCM data. This vortex initiates a flow in the relatively cold boundary layer, which may penetrate the core gas. This resulting non-uniformity of the core region could cause serious discrepancies and give unreliable experimental data. To achieve a homogenous temperature field, an optimised piston crevice was designed using CFD modelling (Ansys fluent). A 2-Dimensional computational moving mesh is assuming an axisymmetric symmetry. The model adopted for this calculation is the laminar flow model and the fluid used was nitrogen. To get the appropriate crevice volume suitable for the present design, an optimisation of the five different crevice volume was modelled which resulted to about 2-10% of the entire chamber volume. The use of creviced piston has shown to reduce the final compressed gas temperature and pressure in the reactor chamber. All the crevice volumes between 2-10% of the chamber volume adequately contained the roll up vortexes, but the crevice volume of 282 mm3 was chosen to be the best in addition to minimising the end gas pressure and temperature drop. The final pressure trace from experiment shows a reasonable agreement with the CFD model at compression and post compression stage.

Original languageEnglish
Article number012018
JournalIOP Conference Series: Materials Science and Engineering
Issue number1
Publication statusPublished - 29 Sept 2017
Event2nd International Conference on Computational Fluid Dynamics in Research and Industry, CFDRI 2017 - Songkhla, Thailand
Duration: 3 Aug 20174 Aug 2017

Bibliographical note

Publisher Copyright:
© Published under licence by IOP Publishing Ltd.

Copyright 2017 Elsevier B.V., All rights reserved.

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering


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