eprintid: 17178 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/71/78 datestamp: 2023-12-19 03:23:37 lastmod: 2023-12-19 03:23:37 status_changed: 2023-12-19 03:07:36 type: article metadata_visibility: show creators_name: Raheem, A.T. creators_name: Aziz, A.R.A. creators_name: Zulkifli, S.A. creators_name: Baharom, M.B. creators_name: Rahem, A.T. creators_name: Ayandotun, W.B. title: Optimisation of operating parameters on the performance characteristics of a free piston engine linear generator fuelled by CNG�H2 blends using the response surface methodology (RSM) ispublished: pub keywords: Compressed natural gas; Crankshafts; Electric generators; Engine pistons; Free piston engines; Surface properties, Engine performance; Free-piston engine; In-cylinder pressures; Linear free piston engine; Linear generators; Operating parameters; Optimisations; Performance; Performance characteristics; Response-surface methodology, Gas emissions note: cited By 16 abstract: The free piston engine linear generator (FPELG) is a simple engine structure with few components, making it a promising power generation system. However, because the engine works without a crankshaft, the handling of the piston motion control (PMC) is the main challenge influencing the stability and performance of FPELGs. In this article, the optimal operating parameters of FPELG for maximising engine performance and reducing exhaust gas emissions were studied. Moreover, the influence of adding hydrogen (H2) to compressed natural gas (CNG) fuel on FPELG performance was investigated. The influence of operating parameters on in-cylinder pressure was also analysed. The single-piston FPELG fuelled by CNG blended with H2 was used to run the experiments. The response surface methodology (RSM), including the central composite design (CCD), was used. Then, adequacy models were developed and verified by ANOVA. Three independent factors on seven responses were utilised for optimisation. Results showed that the optimal operating conditions of lambda, ignition velocity, and injection position were 0.96, 0.53 m/s, and �14.9 mm, respectively. The best-predicted values were as follows: indicated mean effective pressure (IMEP) of 7.6 bar, in-cylinder pressure of 27.87 bar, combustion efficiency of 39.64, CO of 9531.41 ppm, CO2 of 2.4, HC of 551.75 ppm, and NOX of 113.737 ppm. Furthermore, results showed that the experimental data could be fitted well with the predicted quadratic model. © 2021 Hydrogen Energy Publications LLC date: 2022 publisher: Elsevier Ltd official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119437420&doi=10.1016%2fj.ijhydene.2021.10.125&partnerID=40&md5=c2cdb0213333d66f8dbdf2fbf19c3b64 id_number: 10.1016/j.ijhydene.2021.10.125 full_text_status: none publication: International Journal of Hydrogen Energy volume: 47 number: 3 pagerange: 1996-2016 refereed: TRUE issn: 03603199 citation: Raheem, A.T. and Aziz, A.R.A. and Zulkifli, S.A. and Baharom, M.B. and Rahem, A.T. and Ayandotun, W.B. (2022) Optimisation of operating parameters on the performance characteristics of a free piston engine linear generator fuelled by CNG�H2 blends using the response surface methodology (RSM). International Journal of Hydrogen Energy, 47 (3). pp. 1996-2016. ISSN 03603199