In order to estimate the precise performance of the existing gas turbine engine, the component maps with more realistic performance characteristics are needed. Because the component maps are the engine manufacturer’s propriety obtained from very expensive experimental tests, they are not provided to the customers, generally. Therefore, because the engineers, who are working the performance simulation, have been mostly relying on component maps scaled from the similar existing maps, the accuracy of the performance analysis using the scaled maps may be relatively lower than that using the real component maps. Therefore, a component map generation method using experimental data and the genetic algorithms are newly proposed in this study. The engine test unit to be used for map generation has a free power turbine type small turboshaft engine. In order to generate the performance map for compressor of this engine, after obtaining engine performance data through experimental tests, and then the third order equations, which have relationships with the mass flow function, the pressure ratio, and the isentropic efficiency as to the engine rotational speed, were derived by using the genetic algorithms. A steady-state performance analysis was performed with the generated maps of the compressor by the commercial gas turbine performance analysis program GASTURB (Kurzke, 2001). In order to verify the proposed scheme, the experimental data for verification were compared with performance analysis results using traditional scaled component maps and performance analysis results using a generated compressor map by genetic algorithms (GAs). In comparison, it was found that the analysis results using the generated map by GAs were well agreed with experimental data. Therefore, it was confirmed that the component maps can be generated from the experimental data by using GAs and it may be considered that the more realistic component maps can be obtained if more various conditions and accurate sensors would be used.
The purpose of this paper is to analyze the structural stability of an underwater high-speed vehicle. The drag characteristics of a moving body moving at high speed in water were analyzed, and a stability analysis of the structure was performed by applying the non-conservative property according to the driven force in a rocket propulsion environment. To this end, the fluid characteristics that enable high-speed maneuvering in an underwater environment were described, and the structural stability was analyzed by simplifying modeling by increasing the resulting drag. In addition, for high-speed underwater movement, an analysis of the following force according to drag and axial load and the effect on structural stability was conducted by simplifying the structure attached to a specific location when a supercavitation occurs.
10 February 2009 in Journal of Engineering for Gas Turbines and Power
Because an aircraft gas turbine operates under various flight conditions that change with altitude, flight velocity, and ambient temperature, the performance estimation that considers the flight conditions must be known before developing or operating the gas turbine. More so, for the unmanned aerial vehicle (UAV) where the engine is activated by an onboard engine controller in emergencies, the precise performance model including the estimated steady-state and transient performance data should be provided to the engine control system and the engine health monitoring system. In this study, a graphic user interface (GUI) type steady-state and transient performance simulation model of the PW206C turboshaft engine that was adopted for use in the Smart UAV was developed using SIMULINK for the performance analysis. For the simulation model, first the component maps including the compressor, gas generator turbine, and power turbine were inversely generated from the manufacturer’s limited performance deck data by the hybrid method. For the work and mass flow matching between components of the steady-state simulation, the state-flow library of SIMULINK was applied. The proposed steady-state performance model can simulate off-design point performance at various flight conditions and part loads, and in order to evaluate the steady-state performance model their simulation results were compared with the manufacturer’s performance deck data. According to comparison results, it was confirmed that the steady-state model agreed well with the deck data within 3% in all flight envelopes. In the transient performance simulation model, the continuity of mass flow (CMF) method was used, and the rotational speed change was calculated by integrating the excess torque due to the transient fuel flow change using the Runge–Kutta method. In this transient performance simulation, the turbine overshoot was predicted.
In this study, a real-time engine model and a test bench were developed to verify the performance of the EECU (electronic engine control unit) of a turbofan engine. The target engine is a DGEN 380 developed by the Price Induction company. The functional verification of the test bench was carried out using the developed test bench. An interface and interworking test between the test bench and the developed EECU was carried out. After establishing the verification test environments, the startup phase control logic of the developed EECU was verified using the real-time engine model which modeled the startup phase test data with SIMULINK. Finally, it was confirmed that the developed EECU can be used as a real-time engine model for the starting section of performance verification.
About Me
Doctor of Engineering. Professor of Dept. of Aircraft MRO Engineering, Howon University.
Doctor of Engineering. Professor of Dept. of Aircraft MRO Engineering, Howon University.