The examination of injection strategies of jet propellant-8 for compression ignition engine with a low compression ratio

Abstract

Jet Propellant-8 (JP-8) is used as a fuel for standard CI engine instead of diesel oil, especially in military applications on a large scale. For all such applications, the engine regulation parameters are optimal for diesel oil. The properties of kerosene-type fuel, encourage to test different strategies of mixture creation and combustion modes which could be more effective for JP-8 than these elaborated for diesel oil. The paper describes an experiment focused on finding an injection strategy for effective application of JP-8 to a CI engine with low compression ratio. To find an effective way of JP-8 application, the search described in the paper started from the investigation of Low Temperature Combustion (LTC) possibilities, including Homogeneous Charge Compression Ignition (HCCI) engine operation. It led to Partially Premixed Combustion (PPC) with the injection synchronised with the start of mixing controlled phase of combustion. It is also presented how small changes in the injection sequence could heavily influence the combustion phases and very significantly modify the combustion process. For the tests, a naturally aspirated AVL research engine equipped with a common rail system was adapted. The low compression ratio (CR=12:1) was applied. The experiment excluded Exhaust Gas Recirculation (EGR) and mixture dilution with the air. The paper contains the comparison of JP-8 combustion parameters, engine performance and emissions parameters obtained for different injection strategies.