Application of Bond-Graph Method in Microjet Engine Cold Start Modeling to Investigate the Idea of Injecting Compressed Air

This paper presents the application of bond-graph modeling for investigation of the microjet engine in cold starting mode. In this model, the idea of simultaneous usage of the compressed air and electric starter is developed to perform the starting process. For this purpose, the microjet engine is assembled by components which is provided by the engine manufacturer, then a monitoring system in Labview software is developed. Dynamic modeling of the engine cold starting phase is performed by bond graph approach and simulated in 20-sim software. So, the allowable air pressure to inject during the starting process is calculated. The simulation results are then compared with experimental data where a good agreement is observed. These results support the proposed model for further analysis to improve the performance of engine start-up process.