Leakage Flow and Conjugate Heat Transfer Characteristics of Suction Surface Adjustable Guide Vane in Adaptive Cycle Engine

Abstract The adaptive cycle engine (ACE) can effectively improve the economy and acceleration/deceleration characteristics by adjusting the thermodynamic cycle process of an aircraft jet engine. The key technology of the adaptive cycle engine is to achieve adaptive regulation of mass flow and pressure, which relies on the core component of variable geometry gas turbines. At present, the main form of variable geometry turbine is the variable installation angle guide vane turbine. However, practical applications have found that the installation angle guide vane decreases the aerodynamic efficiency due to the through endwall clearance leakage. In addition, the coolant must enter the blade cooling channel through the hollow rotating shaft, resulting in a large pressure loss, and it is difficult to achieve efficient cooling. Therefore, the novel suction surface adjustable guide vane is proposed to improve the aerodynamic efficiency and cooling effectiveness. This paper conducted a study on the leakage flow and conjugate heat transfer characteristics of novel suction surface adjustable guide vane. The three-dimensional numerical steady-state simulations are performed with SST k-ω turbulence model by ANSYS CFX. The variations in parameters such as mass flow rate, aerodynamic losses, solid temperature distribution and leakage film cooling effectiveness are analyzed at different vane openings for both guide vanes. The results indicated that when the rotation angle of the adjustable suction surface was 0 degrees, for guide vane with surface leakage, endwall leakage and both surface leakage and endwall leakage, the mainstream mass flow rates decreased by 0.63%, 1.57% and 2.52%, respectively. When the adjustable surface was rotated by 10 degrees, the mass flow rates decreased by 22.4%. The surface coolant leakage and the endwall coolant leakage had a good cooling effect, and the highest cooling effectiveness is able to reach 0.6.