Prediction and simulation of performance deterioration on off-design point for gas turbine engine

• Main Authors: Han-Sen Kuo, 郭瀚森
• Other Authors: Fan-Mine Yu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/56129111291067645557

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 97 === The study is based on GSP software with its mature characteristics on the simulation of off-design conditions for gas turbine engine. It is used to simulate and predict performance deterioration due to a turbojet axial engine(similar to J85 dry model) suffering from a variety of failure factors in steady state and transient conditions. It is assumed that fuel flow from maximum power to ground idle rotational speed by deceleration then back to maximum by acceleration without using variable geometry system or control bleed valve simultaneously. Four failure cases were simulated which include internal instability owing to “increase tip clearance” and “turbine erosion”, and the external instability owing to “FOD or bird ingestion” and “hot gas ingestion”. All of the critical parameters affecting performance deterioration from these cases have been analyzed and to study the engine failure/malfunctions modes and symptoms. The average percentage of variation for each critical parameter is used as input to GSP components deterioration tabsheet respectively, and to obtain graphical output of performance parameters with compressor efficiency, turbine efficiency, net thrust and thrust specific fuel consumption. The pressure ratio of equilibrium running line and stall line also measured as to relate whether undeterioration or deterioration in order to calculate stall margin by means of compressor characteristic map. In accordance with this results, it is observed that in decelerated transient, both internal instability and external instability factors can create net thrust deterioration. In accelerated transient, net thrust will be temporarily upgraded by the factors due to the inertia effects with the engine in high rotational speed as well as the high mechanical shaft efficiency, however, the final net thrust is shown a deterioration trends on returning to steady state. In addition, a measured method which named “approximate balance for stall margin of undeterioration and deterioration during steady state and transient” is also suggested by this study.