Gokaraju Rangaraju Institute of Engineering & Technology, India
Posters & Accepted Abstracts: Adv Automob Eng
Experiments were performed on a 4-stroke, single cylinder, variable compression ratio (VCR) diesel engine with pure diesel as a baseline fuel and blends of diesel and biodiesel with 0.5% ethyl hexyl nitrate (EHN) at different compression ratios (CR) such as 15:1, 16.5:1, 18:1 and 19.5:1 and at 20% EGR. From experimental investigations, it is found that with increase in CR, better performance is observed. The increase in CR increases the cylinder gas pressure and temperature and also the mixture concentration at the end of the compression stroke. As a result of this, burning rate increases and consequently thermal efficiency increases. Maximum BTE obtained is 32.3% at a compression ratio of 19.5:1 when compared to 30.25% at 16.5:1. However, at higher compression ratios (i.e., at 19.5:1), NOx emissions are higher and also increase in BTE is insignificant. Hence, optimum CR is 18:1.