• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.23-32
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• 2012

The present study is aimed to develop an integrated performance analysis approach for the application of a compressor with variable inlet guide vane (VIGV) and vairable stator vane (VSV) in a small turbofan engine. For the integrated analysis approach, an engine performance analysis program, NPSS and a computer program used for predicting of axial flow compressor performance based on stage stacking method, STGSTK were linked with an optimisation package, Isight. This enables off-design performance analysis for the turbofan engine with VIGV and VSV hence provides the capability to predict stable operation condition of the engine with acceptable surge margin.

• Journal of computational fluids engineering
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• v.16 no.3
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• pp.75-81
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• 2011

The turbo blowers having large power capacity are generally composed of the variable inlet guide vane, the impeller and the variable diffuser. In the present study, the effect of the stagger angles on the aerodynamic performances has been investigated by CFD methods. The design specifications of the reference model having 400kW power were given as 7.43kg/s of mass flow rate, 1.66 of pressure ratio with 12000rpm of impeller rotating speed. As the first simulation parameter, the diffuser vane angle was varied in the range of ${\pm}$20 degree from the initial-design point. The inlet guide vane angles, as the second one, was changed in the range of ${\pm}$40 degree from the initial-design point. The commercial Navier-Stokes solver, ANSYS-CFX, was applied to solve the three-dimensional unsteady flow fields inside the turbo blower. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.539-546
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• 2013

Surge phenomenon can be occurred in a compressor when compressor performance of turbofan engine for an aircraft is changed considerably in a short time on the cases like take-off phase and changing of RPM from idle to maximum, because performance of aircraft engine is changed suddenly. This study is aimed to avoid surge in a compressor. Dynamic simulation in a compressor is modeled by simulink in specific condition. Fuel flow is control input, rpm and air mass flow are expressed in terms of transfer function. Surge margin is obtained by using compressor performance map from NPSS. VIGV(Variable Inlet Guide Vane) is controlled by PD controller with difference between surge margin and reference. Finally this paper verifies IGV can prevent surge phenomenon in a compressor.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.1-8
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• 2012

In this study, numerical method, stage stacking method based on the result of numerical method and scaled stage stacking method have been applied to predict the performance of a multi-stage axial compressor with inlet guide vane. The results obtained through three different methods for off-design conditions were compared with performance test data. And the effect the angle of variable inlet guide vane was also investigated. The three-dimensional numerical simulation has been performed by using flow analysis program, $FLUENT^{TM}$ 6.3 and the performance prediction based on the stage stacking method has been performed with compressor analysis code from NASA.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1211-1214
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• 2004

In this paper, we propose to use variable inlet guide vane as a means of active surge control to solve above problems. There is some advantage. For example, since the inlet guide vanes are already present in POSCO, no additional actuation device is required. We can collect all data easily which is related to the test and can simulate new model using our compressors. We can obtain the result that blow-off valve is opened less 5% and can operate air compressor automatically and more efficiently. Through a simulation example, the effectiveness of the proposed schemes is illustrated.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.52-61
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• 2015

This paper performed a numerical study to analyse the transient performance behavior of a turbofan engine with variable inlet guide vane (IGV) and bleed air schedules. The low bypass ratio mixed flow turbofan engine was considered in this study. For modeling the compressor performance with IGV, the performance maps were generated by using a one-dimensional meanline analysis and feed to the engine simulation program. The IGV and bleed air according to the rotating speed were scheduled to satisfy 10% of surge margin at steady-state condition. The transient engine performance analysis was conducted with the schedules. The engine with IGV schedule showed a higher surge margin and lower turbine inlet temperature than the engine with bleed air schedule during the transient period.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2171-2180
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• 1991

An analysis model for off-design performance of radial inflow turbines with or without variable area guide vane is developed, where two important factors in loss models, total pressure ratio between variable area guide vane exit and scroll casing inlet and rotor loss coefficient are determined without experimental data. The analysis results show that the predicted trends with or without variable area guide vane are consistent with the experimental observations. The comparison of present method with the well-known NASA off-design performance analysis program shows that the mass flow rate and static efficiency by present analysis are in good agreement with those by the NASA program. Therefore, this method can be used to predict off-design performance of radial inflow turbines with validity of the loss models used by present analysis.

• Journal of Hydrogen and New Energy
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• v.24 no.4
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• pp.326-333
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• 2013

This paper presents the performance enhancement of a double-inlet centrifugal blower by the shape optimization of an inlet duct. Two design variables, a length of anti circulation vane and an angles of inlet guide, are introduced to improve the inlet flow uniformity leading to the blower performance. Three-dimensional Navier-Stokes equations are used to analyze the blower performance and the internal flow of the blower. From the shape optimization of the inlet duct of the double-inlet centrifugal blower, the optimal positions of each design variable are determined. Throughout the analysis of sensitivity, it is found that the angle of the inlet guide is more effective than the length of the anti-circulation vane to increase flow uniformity at the outlet of the duct. Efficiency and pressure for the optimal inlet duct shape are successfully increased up to 3.55% and 3.2% compared to those of reference blower at the design flow condition, respectively. Detailed flow field inside the blower is also analyzed and compared.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.9-18
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• 2016

Generally the variable guide vane is used to secure the sufficient operating point in the off-design condition. In this study the inlet guide vane, 1st and 2nd stators in a multi-stage axial compressor are movable to obtain the operating range. So the effects of variable guide vane setting angle on the performance of 2.5 stage axial compressor were investigated at 70 % and 90 % conditions of nominal rotating speed in this paper. The steady-state and unsteady numerical analyses were conducted at each operating condition. The performance map, lost efficiency and flow fields were compared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.237-242
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• 2014

Surge phenomenon can be occurred in a compressor when the performance of turbofan engine for an aircraft is changed considerably such as take-off phase. This study is aimed to avoid surge phenomenon. This paper propose the PID and Fuzzy control System for the turbofan engine with control inputs, the VIGV(Variable Inlet Guide Vane) in closed loop, and the fuel mass flow in open loop. We design the Dynamic modeling, NPSS S-function, which is connection block of simulink between NPSS(Engine analysis program) and Simulink. Finally, we certify the performance to prevent a serge phenomenon in the VIGV control system using the both methods, PID and fuzzy.