Flow field behind a complex total pressure distortion screen

Abstract

The flow field behind a complex total pressure distortion screen is investigated experimentally and numerically. The distortion screen is designed using an established design methodology and fabricated by water-jet cutting technique. The distorted total pressure field behind the screen is quantified by a distortion index parameter, which is evaluated from computations and experiments for several values of inlet Mach number. The root-mean-square error between the target total pressure values and that achieved by the screen design at the aerodynamic interface plane is 4.75%. The evolution of the distorted total pressure field downstream of the screen is presented in detail in terms of radial and circumferential total pressure distributions and their gradients. An alternative interpretation of the distorted total pressure field is made by means of defining a total pressure flux existing behind the screen and expanding it using derivative-moment transformation technique. It is seen that the circumferential vorticity is a major contributing factor to the total pressure flux.

Equivalent simulation method for total pressure distortion of ship inlet

“…Naseri et al (2012) used a jet injector to simulate steady-state circumferential intake distortion on a micro jet engine test rig. With the development of distortion simulation, scholars have proposed new methods such as the delta wing method, blade method, square cylinder method, strip distortion generator, complex total pressure distortion screen, curved edge plate, and swirl chamber method (Mankbadi and Georgiadis, 2015;Yusoof and Deshpande, 2015;Sivapragasam, 2019;Cheng et al, 2020;Song et al, 2021). Wu et al (2022) used the BP ANN method to predict the dynamic distortion flow field of a crescent shaped distortion generator.…”

Effects of Splitting Airfoil’s Aspect Ratio on the Control of Separation and Loss Distribution in a Distortion Generator

“…Thus, the quality of delivered flow by inlet (to the engine) is evaluated by the identification of nonuniformities in the distribution of flow properties at engine face, by which the resulting performance and stability variations are evaluated [1,2]. The total pressure distortion is the most commonly encountered type, and it also has the most deteriorating effect on the compressor performance [3]. With the inlet total pressure distortion, the compressor pressure ratio falls compared with the ideal inlet condition [4].…”

Aerothermal Characterisation of Surface Heat Exchangers for Turbofans

“…Roughness elements -Applicable in all-size wind tunnels -Only 1D control able spacing [134]; (b) Perforated holes in plates [143]; (c) Superimposing metallic meshes [144]; (d) Water cutting [141]; (e) 3D printing [139] Distortion screens have been applied to experiments following different manufacturing approaches. Some basic attempts were made using rods with variable spacing [104,133,134,142], perforating plates with holes of different diameters [143] or welding and superimposing metallic meshes of different porosities [144,145].…”

“…Some basic attempts were made using rods with variable spacing [104,133,134,142], perforating plates with holes of different diameters [143] or welding and superimposing metallic meshes of different porosities [144,145]. Other techniques for circumferential distortion panels are based on water cutting [141]. However, maybe the most complete and easy-to-implement is by 3D printing [112,113,120,139,140,146].…”

“…In terms of when the modified velocity is settled downstream of the screen, Stephens et al [140] showed that, at distances of about one hydraulic diameter, the velocity field was already very similar to the final distribution achieved. Sivapragasam [141] conducted a more detailed investigation and determined that the pressure field and its gradients between two and five diameters downstream remained almost unchanged, whereas the variations were larger for shorter distances.…”