Abstract: A pre-swirl system with a multi-chamber structure is crucial to the secondary air system of an aero engine. The airflow within the pre-swirl system (characterized by high-speed rotation and compressible flow) is complicated. During transient processes in aero engine operation, the pre-swirl system is subjected to upstream fluctuations, which is a less studied aspect. This paper delves into the unsteady flow characteristics within the pre-swirl system. We investigate the influence of different pressure-fluctuation boundary conditions, corresponding to step function, ramp function, and sine function, on the transient response characteristics of the pre-swirl system. The results indicate that the response characteristics are strongly affected by the upstream boundary conditions. An obvious overshoot phenomenon is observed in the actual temperature drop under the step and ramp function conditions. The peak time of the step function is 75% shorter compared to the ramp function. Furthermore, the flow parameters exhibit nonlinear growth during the transient process, emphasizing the need for consideration in future quasi-steady simulations. For the sine function condition, the pressure-fluctuation frequency minimally affects stable values of mass flow rate and actual temperature drop but exerts a substantial influence on the maximum deviation of actual temperature drop of the system. As the frequency increases from 100 Hz to 200 Hz, the maximum deviations for actual temperature drop change from around ±13 K to ±10 K.

过渡态下盖板式预旋系统的数值模拟研究

[1]BenimAC,BrillertD,CaganM,2004.Investigation into the computational analysis of direct-transfer pre-swirl systems for gas turbine cooling.ASME Turbo Expo:Power for Land, Sea, and Air, p.453-460.

[2]BlazekJ,2015.Computational Fluid Dynamics: Principles and Applications.3rd Edition.Elsevier,Amsterdam,the Netherlands.

[3]BonfiglioliA,PaciorriR,2014.Convergence analysis of shock-capturing and shock-fitting solutions on unstructured grids.AIAA Journal,52(7):1404-1416.

[4]CiampoliF,HillsNJ,ChewJW,et al.,2008.Unsteady numerical simulation of the flow in a direct transfer pre-swirl system.ASME Turbo Expo:Power for Land, Sea, and Air, p.1647-1655.

[5]CourantR,FriedrichsK,LewyH,1928.Über die partiellen differenzengleichungen der mathematischen physik.Mathematische Annalen,100(1):32-74(in German).

[6]DingST,WangZY,QiuT,et al.,2018.Probabilistic failure risk assessment for aeroengine disks considering a transient process.Aerospace Science and Technology,78:696-707.

[7]DittmannM,GeisT,SchrammV,et al.,2002.Discharge coefficients of a preswirl system in secondary air systems.Journal of Turbomachinery,124(1):119-124.

[8]DuttonJC,CoverdillRE,1997.Experiments to study the gaseous discharge and filling of vessels.The International Journal of Engineering Education,13(2):123-134.

[9]GallarL,CalcagniC,LlorensC,et al.,2011.Time accurate modelling of the secondary air system response to rapid transients.Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering,225(8):946-958.

[10]GanCY,DingST,QiuT,et al.,2024.Model-based safety analysis with time resolution (MBSA-TR) method for complex aerothermal–mechanical systems of aero-engines.Reliability Engineering & System Safety,243:109864.

[11]GongWB,LiuGW,WangJY,et al.,2022.Aerodynamic and thermodynamic analysis of an aero-engine pre-swirl system based on structure design and performance improvement.Aerospace Science and Technology,123:107466.

[12]KarabayH,ChenJX,PilbrowR,et al.,1999.Flow in a “cover-plate” preswirl rotor–stator system.Journal of Turbomachinery,121(1):160-166.

[13]KarabayH,WilsonM,OwenJM,2001.Predictions of effect of swirl on flow and heat transfer in a rotating cavity.International Journal of Heat and Fluid Flow,22(2):143-155.

[14]KarnahlJ,von WolfersdorfJ,ThamKM,et al.,2012.Computational fluid dynamics simulations of flow and heat transfer in a preswirl system: influence of rotating-stationary domain interface.Journal of Engineering for Gas Turbines and Power,134(5):052502.

[15]KimS,LeeJ,KimD,et al.,2022.Effect of fillet radius of receiver hole on the performance of gas turbine pre-swirl system.Journal of Mechanical Science and Technology,36(12):6073-6081.

[16]LeeJ,LeeH,ParkH,et al.,2021.Design optimization of a vane type pre-swirl nozzle.Engineering Applications of Computational Fluid Mechanics,15(1):164-179.

[17]LiaoGH,WangXJ,LiJ,2014.Numerical investigation of the pre-swirl rotor–stator system of the first stage in gas turbine.Applied Thermal Engineering,73(1):940-952.

[18]LinAQ,LiuGW,YuXX,et al.,2022.Comprehensive investigations on fluid flow and heat transfer characteristics of a high-speed rotating turbine disk cavity system of aero-engine.International Communications in Heat and Mass Transfer,136:106170.

[19]LiuGW,LiuYX,KongXZ,et al.,2017.A new design of vane-shaped hole pre-swirl nozzle.Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy,231(1):14-24.

[20]LiuYX,LiuGW,KongXZ,et al,2018.Experimental testing and numerical analysis on the nozzle effects in preswirl system.Journal of Propulsion and Power,34(4):‍1015-1025.

[21]LiuYX,YueBZ,KongXZ,et al.,2021.Design and performance analysis of a vane shaped rotating receiver hole in high radius pre-swirl systems for gas turbine cooling.Aerospace Science and Technology,115:106807.

[22]LiuYX,LuBY,KongXZ,et al.,2023.Effects of the misalignment and axial gap on performance of a cover-plate pre-swirl system with impellers for gas turbine cooling.Physics of Fluids,35(10):105110.

[23]MaoSS,WangSF,HuWX,2019.Study on transient response characteristics of rotor-stator cavity with typical intake function.Journal of Propulsion Technology,40(1):175-183(in Chinese).

[24]MenterFR,1994.Two-equation eddy-viscosity turbulence models for engineering applications.AIAA Journal,32(8):1598-1605.

[25]NicholasTEW,PernakMJ,ScobieJA,et al.,2023.Transient heat transfer and temperatures in closed compressor rotors.Applied Thermal Engineering,230:120759.

[26]NikolaidisT,WangHN,LaskaridisP,2020.Transient modelling and simulation of gas turbine secondary air system.Applied Thermal Engineering,170:115038.

[27]OwenJM,PincombeJR,RogersRH,1985.Source–sink flow inside a rotating cylindrical cavity.Journal of Fluid Mechanics,155:233-265.

[28]PoppO,ZimmermannH,KutzJ,1998.CFD analysis of coverplate receiver flow.Journal of Turbomachinery,120(1):43-49.

[29]RoachePJ,1998.Verification of codes and calculations.AIAA Journal,36(5):696-702.

[30]RoyCJ,McWherter-PayneMA,OberkampfWL,2003.Verification and validation for laminar hypersonic flowfields, part 1: verification.AIAA Journal,41(10):1934-1943.

[31]ShenWJ,WangSF,2022.Large eddy simulation of turbulent flow and heat transfer in a turbine disc cavity with impellers.International Communications in Heat and Mass Transfer,139:106463.

[32]ThomasJL,DiskinB,RumseyCL,2008.Towards verification of unstructured-grid solvers.AIAA Journal,46(12):3070-3079.

[33]WilcoxDC,1988.Reassessment of the scale-determining equation for advanced turbulence models.AIAA Journal,26(11):1299-1310.

[34]ZhangK,NaguibAM,2011.Effect of finite cavity width on flow oscillation in a low-Mach-number cavity flow.Experiments in Fluids,51(5):1209-1229.

[35]ZimmermannH,1990.Some aerodynamic aspects of engine secondary air systems.Journal of Engineering for Gas Turbines and Power,112(2):223-228.