The object of this paper is to provide a reliable tool to simulate the stationary and transient operation performances in multistage axial compression systems, especially poststall behavior. An adapted version of the 1D Euler equations with additional source terms is solved by a time marching and control volume method. The equations are discretized at midspan both inside the blade rows and the nonbladed regions, along the real flow path geometry. The source terms express the blade-flow interactions and are estimated by calculating the velocity triangles for each blade row. Loss coefficient and deviation models are supplied by empirical correlations and are compared to experimental data in all flow regions. Transient simulations are carried and compared to the experimental results for several values of parameter B. The flow mechanism inside the compressor during a surge cycle is also shown. 1. Introduction The compression system is an important component of a gas turbine engine. During the operation of axial multistage compressors, instabilities such as surge and rotating stall were observed in many experimental tests. However, such tests are expensive and not practical for preliminary design purpose. Numerical simulations of poststall performances of compression system are needed and useful in the design phase. In this paper, a reliable numerical tool is presented to simulate the instability behavior and to analyze the flow mechanism inside the compressor during poststall process. This tool is only based on the compressor geometry and empirical correlations to simulate the poststall performance. The mesh cells are not only distributed between blade rows, but also inside of each blade row, allowing for a detailed representation of the flow field. An adapted version of Euler equations, mass, meridional momentum, circumferential momentum, and energy balances being applied for each control volume at mean radius. These equations are solved by a time-marching, finite-volume method [1]. The source terms expressing the blade-flow interactions are estimated by calculating the velocity triangles for each blade row with the help of empirical correlations. The test compressor rig of Day is chosen to validate this model because of the detailed experiment results [2]. The steady characteristic curve of the compressor is predicted and is compared to the experiments. Dynamic simulations of the compression system are also carried out to predict the poststall performance and to validate the present tool. The flow mechanism inside of the compression system during one
References
[1]
O. Léonard and O. Adam, “A quasi-one-dimensional CFD model for multistage turbomachines,” Journal of Thermal Science, vol. 17, no. 1, pp. 7–20, 2008.
[2]
I. J. Day, “Axial compressor performance during surge,” AIAA Journal of Propulsion and Power, vol. 10, no. 3, pp. 329–336, 1994.
[3]
E. M. Greitzer, “Review—axial compressor stall phenomena,” Journal of Fluids Engineering, Transactions of the ASME, vol. 102, no. 2, pp. 134–151, 1980.
[4]
E. M. Greitzer, “Surge and rotating stall in axial flow compressors. Part I: theoretical compression system model,” Journal of Engineering for Power, vol. 98, pp. 190–217, 1976.
[5]
E. M. Greitzer, “Surge and rotating stall in axial flow compressors. Part II: experimental results and comparison with theory,” Journal of Engineering For Power, vol. 98, no. 2, Article ID article id, pp. 199–211, 1976.
[6]
M. W. Davis, A stage-by-stage post-stall compression system modeling technique: methodology, validation, and application, Ph.D. thesis, Virginia Polytechnic Institute and State University, 1987.
[7]
M. Morini, M. Pinelli, and M. Venturini, “Development of a one-dimensional modular dynamic model for the simulation of surge in compression systems,” Journal of Turbomachinery, vol. 129, no. 3, pp. 437–447, 2007.
[8]
H. Takata and S. Nagano, “Nonlinear analysis of rotating stall,” Journal of Engineering for Power, vol. 94, no. 4, pp. 279–293, 1972.
[9]
F. K. Moore and E. M. Greitzer, “A theory of post-stall transients in axial compression system: Part I: development of equations,” ASME paper 85-GT-171, 1985.
[10]
J. W. Lindau and A. K. O. Owen, “Nonlinear quasi-three-dimensional modeling of rotating stall and surge,” AIAA paper 97-2772, 1997.
[11]
V. Garnier and J. F. Escuret, “Numerical simulations of surge and rotating stall in multi-stage axial-flow compressors,” AIAA paper 94-3202, 1994.
[12]
N. Tauveron, M. Saez, P. Ferrand, and F. Leboeuf, “Axial turbomachine modelling with a 1D axisymmetric approach. Application to gas cooled nuclear reactor,” Nuclear Engineering and Design, vol. 237, no. 15-17, pp. 1679–1692, 2007.
[13]
S. Lieblein, “Experimental flow in two-dimensional cascades,” NASA SP-36, 1965.
[14]
H. F. Creveling and R. H. Carmody, “Axial-flow compressor computer program for calculating off-design performance,” NASA CR-72472, 1968.
[15]
H. L. Moses and S. B. Thomason, “An approximation for fully stalled cascades,” Journal of Propulsion and Power, vol. 2, no. 2, pp. 188–189, 1986.
[16]
I. J. Day, E. M. Greitzer, and N. A. Cumpsty, “Prediction of compressor performance in rotating stall,” ASME Journal of Engineering for Power, vol. 100, no. 1, pp. 1–14, 1978.
[17]
J. P. Longley, “Calculating stall and surge transients,” ASME paper GT-2007-27378, 2007.
[18]
R. N. Gamache and E. M. Greitzer, “Reverse flow in multistage axial compressors,” AIAA paper 86-1747, 1986.
[19]
R. V. Chima, “A three-dimensional unsteady CFD model of compressor stability,” NASA TM 2006-214117, 2006.
