To meet the requirements over a broad flight envelope, rear fan of three bypass variable cycle engine requires extensive flow adjustment. This study proposes tandem stator configuration for front outlet stage. Our research investigates geometric features, including hub clearance size, rotation, and blade (RB) stagger angle, their effects on both performance internal flow. Numerical results show that introduction has negligible effect total pressure ratio isentropic efficiency fan. The...

In order to advance the understanding of fundamental mechanisms axial skewed slot casing treatment and their effects on subsonic axial-flow compressor flow field, coupled unsteady through a rotor was simulated with state-of-the-art multiblock solver. The computational results were first compared available measured data, that showed numerical procedure calculates overall effect correctly. Then, numerically obtained fields interrogated identify physical mechanism responsible for improvement in...

Designing the high-performance, high-subsonic airfoils suitable for different Reynolds number flow is major challenge high-altitude long-endurance drones and ultra-high altitude solar aircraft. To overcome difficulties, this paper proposed a set of aerodynamic optimization design methods that combine improved category shape function transformation method, parallel computational fluid dynamics, an whale algorithm. This approach achieves high modeling accuracy, efficiency, strong ability....

Pipe diffusers with several different geometries were designed for a highly loaded centrifugal compressor originally using wedge diffuser. Parametric studies on the effect of pipe diffuser performance by varying inlet-to-impeller exit radius ratio, throat length, divergence angle, and area performed state-of-the-art multiblock flow solver. An optimum design was obtained from parametric study, numerical results indicate that this has remarkable advantageous effects performance. Furthermore,...

High-pressure ratio centrifugal compressors’ diffusers face challenges from high-velocity, non-uniform flow at the impeller outlet, decreasing efficiency and stall margin. To address this, this paper presents a novel vaned diffuser passage design method that successfully improved compressor’s performance. An optimization using axisymmetric hub contours NURBS curves was applied to modify diffuser’s design. After optimization, compressor peak increased by 0.78%, margin expanded 12.8% 20.4%....

The turbulence intensity of the high-pressure turbine inlet plays an important role in development secondary flow and boundary layer evolution passage. Unfortunately, current research often overlooks coupling effect between separation endwall flow, lacks comprehensive exploration loss variation. To complement existing research, this study utilizes numerical simulation techniques to investigate cascades under varying intensities, with experimental results as basis. Furthermore, relationship...

The laminar-turbulent transition process on the compressor blade surface is often induced by laminar separation flow at low Reynolds number ( Re). In present study, numerical simulations were conducted to investigate structure of bubble and its effects profile loss a high subsonic airfoil under different Re conditions, mechanism for performance deterioration was clarified. Besides, redesigned obtain series airfoils with loading distributions, aerodynamic these compared analyzed in detail....

Experimental investigation has been performed to study the leakage and wear characteristics of carbon seal working at high circumferential speed. To expand scope application, two newly designed seals were compared: #1 Carbon Seal (CS1) with inner diameter 136 mm including 4 segments, #2 (CS2) 212 6 segments. Air tests firstly conducted in Medium-speed Test Rig. The pressure ratio changed from 1.04 2.02 rotating speed varying 0 18300 r/min. Of paramount concern was durability test, 300 h...

Flow separations in the vaned diffuser play a critical role stall margin of centrifugal compressors. To extend stable operating range highly loaded compressor, flow control technique locating slot near diffuser's leading edge is proposed. A parametric study geometry variations, terms slotted portion depth and length, carried out to summarize trend compressor performance reveal corresponding physics related geometries. The design methodology concluded provide guideline for improvement by...

To improve fishtail pipe diffuser outflow uniformity, deswirlers and splitters are added inside after passages for a compact centrifugal compressor. The influence of clocking effects between the deswirler passage is first studied to find optimum position. performances these two configurations then compared, their loss mechanisms determined. Finally, compressor exit flow conditions estimated. Either adding or tends degrade performance. intensity vortices in increased; therefore, losses...