A pneumatic piston-released rapid compression machine for chemical kinetics studies at elevated pressure and low to intermediate temperatures

Abstract

This work presents a pneumatically operated piston released rapid compression machine (PRRCM) designed at the University of Sheffield that introduces a new set of pneumatic systems to lock/release the piston from its initial position. It is pneumatically operated to compress gas mixture to an adiabatically thermodynamic state and stopped hydraulically. The range of compression ratios of the facility is between 4.4 and 20. The end of compressed gas temperature, T c and pressure, P c obtained within the facility is approximately 1000 K and 22 bar respectively. The performance of the Sheffield piston released rapid compression machine (SHEF-PRRCM) facility has been characterised to ensure a high level of fidelity of experimental data over a range of test conditions. The performance test was conducted for a nonreactive test using nitrogen and argon, the result demonstrated a repeatable pressure trace. Repeatability test for the reactive mixtures was also demonstrated. Further study on ignition characteristics of aviation fuel (Jet A-1) and Banner NP1014 known as Bannersol in SHEF-PRRCM was conducted over T c of 723 K ⩽ T c ⩽ 884 K, P c = 6 and 10 bar at ϕ = 0.75 and 1.0. The influence of pressure, temperature and equivalence ratio was seen on the oxidation of Jet A-1 and Bannersol. The results showed that Bannersol displayed a negative temperature coefficient behaviour and has higher reactivity than Jet A-1. Besides, a comparative analysis of the current facility with other facilities in literature was carried out, the result showed a fair deviation of the current data from literature and these could be attributed to the inherent non-ideality of heat transfer effects in different rapid compression machine and fairly slight differences in the condition tested. This work has demonstrated the competence of the current facility to carry out further studies on combustion and validation of the chemical kinetics of hydrocarbon fuels.