An unsteady, moving mesh CFD simulation for Harrier hot-gas ingestion control analysis

Hot gas ingestion (HGI) can be a problematic feature of short take-off vertical landing (STOVL) aircraft during the descent phase of landing, or while on the ground. The hot exhaust gases from the downwards pointing nozzles can be re-ingested into the engine intakes, causing power degradation or reduced engine surge margin. The flow-fields that characterise this phenomenon are complex, with supersonic impinging jets and cross-flows creating large ground vortices and fountain up-wash flows. A flow solver has been developed to include a suitable linear mesh deformation technique for the descending aircraft configuration. The code has been applied to predict the occurrence of HGI, by simulating experimental results from a 1/15th scale model of a descending Harrier. This has enabled an understanding of the aerodynamic mechanisms that govern HGI, in terms of the near-field and far-field effects and their impact on the magnitude of temperatures at the engine intake. This paper presents three sets of CFD results. First a validation exercise shows predicted results from the twin-jet with intake in crossflow test-case. This is an unsteady Reynolds averaged Navier Stokes (URANS) solution for a static geometry (there is no moving mesh). This allows comparison with experiment. Secondly, a full descent phase URANS Spalart-Allmaras (SA) turbulence model calculation is done on an 8·5m cell mesh for half the flow domain of the Harrier model and test-rig without dams/strakes. This shows how the HGI flow mechanisms affect the engine intake temperature profiles, for the case where there are no flow control methods on the underside of the aircraft. Thirdly, the full descent phase URANS SA turbulence model calculation is done on a 22·4m cell mesh for the full flow domain of the Harrier model and test-rig, with the dam/strake geometry included in the structured mesh region.

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HISTORY OF UTILIZATION OF THE COMPUTATIONAL FLUID DYNAMICS METHOD FOR STUDY PICO HYDRO TYPE CROSS-FLOW

Indonesian Journal of Engineering and Science ◽

10.51630/ijes.v2i1.11 ◽

2021 ◽

Vol 2 (1) ◽

pp. 017-024

Author(s):

Dendy Adanta ◽

Dewi Puspita Sari ◽

Nura Muaz Muhammad ◽

Aji Putro Prakoso

Keyword(s):

Relative Error ◽

Turbulence Model ◽

Rural Areas ◽

Cfd Simulation ◽

Fluid Dynamic ◽

Electrical Power ◽

Cross Flow ◽

Moving Mesh ◽

Absolute Relative Error ◽

The Absolute

Energy crisis in particular, electricity in the isolated rural areas of Indonesia is a very crucial issue that needs to be resolve through electrification . Compared to other options, pico hydro cross-flow turbine (CFT) is the better option to provides electrical power for the isolated rural areas. Studies to improve CFT performance can be undertaken analytically, numerically, experimentally, or a combination of those methods. However, the development of computer technology makes numerical simulation studies have become increasingly frequent. This paper describes the utilization of the computational fluid dynamic (CFD) approach in the pico hydro CFT method. This review has resulted that the recommended Renormalization Group (RNG) k-ε turbulence model for CFT CFD simulation because its absolute relative error is lower than standard k-ε and transitional Shear Stress Transport (SST). The absolute relative error for the RNG k-ε turbulence model of 3.08%, standard k-ε of 3.19%, and transitional SST of 3.10%. While for the unsteady approach, the six-degrees of freedom (6-DoF) are considered because more accurate than moving mesh. The absolute relative error for 6-DoF of 3.1% and moving mesh of 9.5%. Thus, based on the review, the RNG k-ε turbulence model and 6-DoF are proposed for the pico hydro CFT CFD study.

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CFD Analysis of Hot Gas Ingestion Mechanisms for the Vertical Descent Phase of a Harrier Aircraft

Volume 2: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Controls, Diagnostics and Instrumentation; Environmental and Regulatory Affairs ◽

10.1115/gt2006-90766 ◽

2006 ◽

Cited By ~ 1

Author(s):

G. A. Richardson ◽

W. N. Dawes ◽

A. M. Savill

Keyword(s):

Near Field ◽

Impinging Jets ◽

Scale Model ◽

Cambridge University ◽

Hot Gas ◽

Surge Margin ◽

Engineering Department ◽

Cfd Method ◽

Configuration Changes ◽

Problematic Feature

Hot Gas Ingestion (HGI) can be a problematic feature of STOVL aircraft during the descent phase of landing, or while on the ground. The hot exhaust gases from the downwards pointing nozzles can be re-ingested into the engine intakes, causing power degradation or reduced engine surge margin. The flow-fields that characterise this phenomenon are complex, with supersonic impinging jets and cross-flows creating large ground vortices and fountain up-wash flows. As a partner in the PUMA DARP (Unsteady Methods Focus Group), the Cambridge University Engineering department CFD Lab are trying to model this flow-field in order to validate the Rolls-Royce HYDRA CFD code against experimental data obtained from detailed Rolls-Royce HGI tests. The HYDRA code has been developed to include a suitable mesh deformation technique for the descending aircraft configuration. The code is applied to predict the occurrence of HGI, by simulating experimental results from a 1/15th scale model of a descending Harrier. Based on these computational results, this paper studies the aerodynamic mechanisms that govern HGI, in terms of the near-field and far-field effects and their impact on the magnitude of temperatures at the engine intake. The trends in experimental engine intake temperature profiles are explained by analysis of these mechanisms. Following a more thorough validation of these results, the HYDRA code will provide a valuable tool for predicting the occurrence of HGI. The CFD method can then be used for the analysis of other STOVL aircraft as well as configuration changes aimed at preventing HGI.

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A stable method for 4D CT-based CFD simulation in the right ventricle of a TGA patient

Russian Journal of Numerical Analysis and Mathematical Modelling ◽

10.1515/rnam-2020-0026 ◽

2020 ◽

Vol 35 (5) ◽

pp. 315-324

Author(s):

Yuri Vassilevski ◽

Alexander Danilov ◽

Alexander Lozovskiy ◽

Maxim Olshanskii ◽

Victoria Salamatova ◽

...

Keyword(s):

Right Ventricle ◽

Cfd Simulation ◽

Fluid Motion ◽

4D Ct ◽

Post Surgery ◽

Surgery Patient ◽

Time Dependent Domain ◽

Flow Domain ◽

The Right ◽

Dependent Domain

AbstractThe paper discusses a stabilization of a finite element method for the equations of fluid motion in a time-dependent domain. After experimental convergence analysis, the method is applied to simulate a blood flow in the right ventricle of a post-surgery patient with the transposition of the great arteries disorder. The flow domain is reconstructed from a sequence of 4D CT images. The corresponding segmentation and triangulation algorithms are also addressed in brief.

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Introducing a New Test Rig for Film Cooling Measurements With Realistic Hole Inflow Conditions

Volume 5C: Heat Transfer ◽

10.1115/gt2017-63585 ◽

2017 ◽

Cited By ~ 2

Author(s):

Marc Fraas ◽

Tobias Glasenapp ◽

Achmed Schulz ◽

Hans-Jörg Bauer

Keyword(s):

Film Cooling ◽

Gas Flow ◽

Test Rig ◽

Hot Gas ◽

Cooling Hole ◽

Measurement Principle ◽

Density Ratios ◽

Operational Range ◽

Film Cooling Holes

Further improvements in film cooling require an in-depth understanding of the influencing parameters. Therefore, a new test rig has been designed and commissioned for the assessment of novel film cooling holes under realistic conditions. The test rig is designed for generic film cooling studies. External hot gas flow as well as internal coolant passage flow are simulated by two individual flow channels connected to each other by the cooling holes. Based on a similarity analysis, the geometry of the test rig is scaled up by a factor of about 20. It furthermore offers the possibility to conduct experiments at high density ratios and realistic approach flow conditions at both cooling hole exit and inlet. The operational range of the new test rig is presented and compared to real engine conditions. It is shown that the important parameters are met and the transfer-ability of the results is ensured. Special effort is put onto the uniformity of the approaching hot gas flow, which will be demonstrated by temperature and velocity profiles. A first measurement of the heat transfer coefficient without film cooling is used to demonstrate the quality of the measurement principle.

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CFD simulation and experimental analysis of erosion in a slurry tank test rig

EPJ Web of Conferences ◽

10.1051/epjconf/20134501009 ◽

2013 ◽

Vol 45 ◽

pp. 01009 ◽

Cited By ~ 2

Author(s):

Mehdi Azimian ◽

Hans-Jörg Bart

Keyword(s):

Experimental Analysis ◽

Cfd Simulation ◽

Test Rig ◽

Tank Test

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Investigation of Film Cooling Using Time-Resolved Stereo Particle Image Velocimetry

Volume 7B: Heat Transfer ◽

10.1115/gt2020-14403 ◽

2020 ◽

Author(s):

Katharina Stichling ◽

Maximilian Elfner ◽

Hans-Jörg Bauer

Keyword(s):

Particle Image Velocimetry ◽

Film Cooling ◽

Particle Image ◽

Density Ratio ◽

Test Rig ◽

Time Resolved ◽

Hot Gas ◽

Image Velocimetry ◽

Stereo Particle Image Velocimetry ◽

Cooling Air

Abstract In the present study an existing test rig at the Institute of Thermal Turbomachinery (ITS), Karlsruhe Institute of Technology (KIT) designed for generic film cooling studies is adopted to accommodate time resolved stereoscopic particle image velocimetry measurements. Through a similarity analysis the test rig geometry is scaled by a factor of about 20. Operating conditions of hot gas and cooling air inlet and exit can be imposed that are compliant with realistic engine conditions including density ratio. The cooling air is supplied by a parallel-to-hot gas coolant flow-configuration with a coolant Reynolds number of 30,000. Time-resolved and time-averaged stereo particle image velocimetry data for a film cooling flow at high density ratio and a range of blowing ratios is presented in this study. The investigated film cooling hole constitutes a 10°-10°-10° laidback fan-shaped hole with a wide spacing of P/D = 8 to insure the absence of jet interaction. The inclination angle amounts to 35°. The time-resolved data indicates transient behaviour of the film cooling jet.

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