Studies Of Anaerobic Internal Combustion Engine Using Direct Injection Of Liquid Monopropellant

This article describes the design and experimentation of a new anaerobic internal combustion engine using direct injection of liquid monopropellant. Specifically, the use of monopropellant post-injection allows the control of the profile P - V of the cycle, which significantly increases the mean effective pressure (indicated mean effective pressure) and the power density of the engine. The monopropellant used was isopropyl nitrate, which is the first known demonstration of a piston engine using this monopropellant for anaerobic operation. The engine power has been modulated with post-injection strategy to modify the P - V cycle profile to obtain a constant-pressure combustion in anaerobic mode. Experiments were performed using an engine with a single piston with a effective swept volume of 45 cm(3), at an operating frequency of 2 Hz. The prototype engine has achieved an indicated mean effective pressure of up to 4.4 MPa and an indicated power up to 400 W. The indicated thermodynamic efficiency of the engine is found to be about 13% based on the isopropyl nitrate heat of explosion. The indicated specific fuel consumption of the engine is 2.5 mg/J, which represents a conversion efficiency of 49% based on the isopropyl nitrate specific energy.