In-Cylinder Thermodynamic Analysis for Performance Engine Development

This research describes several data processing and analysis techniques that can be used to quantify indicated torque losses associated with in-cylinder thermodynamic events. The detailed thermodynamic techniques are intended to aid the development of performance engines under high-load conditions. This study investigates potential IMEP gains that could be made to an engine based on evaluating cylinder and manifold pressure data collected during wide-open-throttle operation. Examination of the data can guide engine design changes by exposing inefficiencies that may have otherwise gone unnoticed. Examples of calibration adjustments and physical intake and exhaust manifold design changes are also presented to validate the data analysis techniques presented. The research data sets were recorded using a 5.3L V8 engine in conjunction with a highly-controlled transient dynamometer. Fast-response pressure transducers were used to measure crank angle resolved cylinder and manifold pressure over continuous engine speed sweeps. Data evaluation software was developed and used to analyze the data after they were collected. Through the evaluation of many engine parameters including: indicated torque, intake and exhaust manifold tuning, gas exchange, turbulence intensity, combustion phasing, etc. many sources of inefficiency were identified from the baseline engine configuration. The techniques described provide insight that enables both calibration and design changes which increase the engine torque output.