An experimental investigation of S-duct diffusers for high-speed propfans

Little, B. H.; Trimboli, W.

doi:10.2514/6.1982-1123

Cited by 8 publications

(6 citation statements)

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“…In early stages, experiments were the major methods in the S-duct intake studies [2][3][4][5]. With the development of numerical calculation technology, CFD has been one of the most promising and practical methods for intake design [6].…”

Section: Introductionmentioning

confidence: 99%

Numerical Optimization of Electromagnetic Performance and Aerodynamic Performance for Subsonic S-Duct Intake

Wang

2022

Aerospace

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In order to improve the performance of subsonic unmanned aerial vehicle (UAV), a knapsack S-duct intake has been designed. The influences of an S-bend diffuser on aerodynamic performance and electromagnetic performance were analyzed firstly. The viscous flow field has been simulated by solving Favre averaged Navier–Stokes equations using a shear stress transport (SST) k-ω turbulence model. The surface current has been simulated by solving Maxwell equations using a multi-level fast multipole method (MLFMM). The multi-objective optimization of the S-duct intake was studied by using the diffuser as the optimized object. The parametric expression of the diffuser model was realized using the fourth order function geometric representation technique. The efficient model based on the Kriging model and non-dominated sorting genetic algorithm-Ⅱ (NSGA-Ⅱ) were used to accelerate the optimization progress. By analyzing the results of an optimal intake chosen from the Pareto front, the total pressure distortion (TPD) index DC60 has decreased by 0.24 at the designed Mach number of 0.9, and the average Radar Cross Section (RCS) has decreased by 2db at the frequency of 3GHz. The optimized S-duct intake could have both excellent aerodynamic performance and electromagnetic performance at various complex conditions.

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Section: Introductionmentioning

confidence: 99%

Numerical Optimization of Electromagnetic Performance and Aerodynamic Performance for Subsonic S-Duct Intake

Wang

2022

Aerospace

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“…However, the propeller effect on the flow field in S-shaped intake of is rarely studied. As the lip of the turboprop engine intake is close to the propeller rotating plane [15][16][17], the propeller periodically pushes air into the intake, which inevitably affects the engine performance.…”

Section: Introductionmentioning

confidence: 99%

Influence of Propeller Slipstream on the Flow Field of S-Shaped Intake

Ren

Liu

2021

International Journal of Aerospace Engineering

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For turboprop engine, the S-shaped intake affects the engine performance and the propeller is not far in front of the inlet of the S-shaped intake, so the slipstream inevitably affects the flow field in the S-shaped intake and the engine performance. Here, an S-shaped intake with/without propeller is studied by solving Reynolds-averaged Navier-Stokes equation employed SST k-ω turbulence model. The results are presented as time-averaged results and transient results. By comparing the flow field in S-shaped intake with/without propeller, the transient results show that total pressure recovery coefficient and distortion coefficient on the AIP section vary periodically with time. The time-averaged results show that the influence of propeller slipstream on the performance of S-shaped intake is mainly circumferential interference and streamwise interference. Circumferential interference mainly affects the secondary flow in the S-shaped intake and then affects the airflow uniformity; the streamwise interference mainly affects the streamwise flow separation in the S-shaped intake and then affects the total pressure recovery. The total pressure recovery coefficient on the AIP section for the S-shaped intake with propeller is 1%-2.5% higher than that for S-shaped intake without propeller, and the total pressure distortion coefficient on the AIP section for the S-shaped intake with propeller is 1%-12% higher than that for the S-shaped intake without propeller. However, compared with the free stream flow velocity ( Ma = 0.527 ), the influence of the propeller slipstream belongs to the category of small disturbance, which is acceptable for engineering applications.

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“…In this research, a 2D analysis code of potential flow for the outside of the boundary layer and a boundary-layer solution code and their coupling The use of the vortex generator in the lower wall of the duct had a relatively large effect on the flow core at the outlet and the output stream was somewhat more uniform. Little and colleagues [2] investigated the experimental flow of a s-duct at the entrance of a high speed jerk motor. They tested three different shapes on a motor, measuring the total and static pressure distribution at the outlet The ducts obtained the output deformation rate.…”

Section: Introductionmentioning

confidence: 99%

Optimization of S-Shaped Air Intake by Computational Fluid Dynamics

Parhrizkar¹,

Aminjan²,

Doustdar³

et al. 2019

IJFMTS

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Due to the presence of air intakes outside the body of some missiles with research objectives as well as some unmanned aerial, the use of the air intake duct in S-shaped is necessary and therefore the air flow quality must be determined, with the most important parameters being the total drop and distortion is from the beginning of the air intake until the delivery phase to the engine. In this research, it has been determined that the optimum air intake geometry is determined according to the dimensions of a unmanned aerial. Therefore, we first tried to optimize the geometry of S-shaped air intake and then optimize this geometry based on the reduction of total pressure drop. The computational grid with ICEM software and mesh analysis by computational fluid dynamics (Fluent software) has been done. Given that the intake of unmanned aerial was considered in this study, Mach flight is considered 0.3. Since the output section is actually the same section of the motor, whose cross section is constant, it has been considered in optimizing the inlet section and the wall. By optimizing geometry, the total pressure drop dropped to about half. Given the fact that the optimization repetition resulted in undesirable changes in geometry, optimization of geometry was not repeated. Additionally, by comparing the optimized geometry with the initial geometry, It is known that the slow rotation of the flow (the lower rotation angle) reduces the total pressure drop and reduces the amount of distortion. In the end, the results of the numerical solution with the experimental results presented by NASA have been investigated, which indicates that the numerical solution is desirable.

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An experimental investigation of S-duct diffusers for high-speed propfans

Cited by 8 publications

References 0 publications

Numerical Optimization of Electromagnetic Performance and Aerodynamic Performance for Subsonic S-Duct Intake

Numerical Optimization of Electromagnetic Performance and Aerodynamic Performance for Subsonic S-Duct Intake

Influence of Propeller Slipstream on the Flow Field of S-Shaped Intake

Optimization of S-Shaped Air Intake by Computational Fluid Dynamics

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