High-fidelity prediction of flight trajectories of plate-type debris in boundary layer winds

2021 ◽  
Vol 217 ◽  
pp. 104727
Author(s):  
Dikshant Saini ◽  
Behrouz Shafei
Keyword(s):  
Boundary Layer ◽  
High Fidelity ◽  
Flight Trajectories ◽  
Plate Type

Cost-effective and high-fidelity method for turbulent transition in compressible boundary layer

2021 ◽  
Vol 108 ◽  
pp. 106367
Author(s):  
Jiseop Lim ◽  
Minwoo Kim ◽  
Seungtae Kim ◽  
Solkeun Jee ◽  
Donghun Park
Keyword(s):  
Boundary Layer ◽  
Cost Effective ◽  
High Fidelity ◽  
Compressible Boundary Layer ◽  
Turbulent Transition

scholarly journals Thermal Hydraulic and Neutronics Coupling Analysis for Plate Type Fuel in Nuclear Reactor Core

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Linrong Ye ◽  
Mingjun Wang ◽  
Xin’an Wang ◽  
Jian Deng ◽  
Yan Xiang ◽  
...  
Keyword(s):  
Nuclear Reactor ◽  
Reactor Core ◽  
Coupling Method ◽  
High Fidelity ◽  
Monte Carlo Code ◽  
Coupling Analysis ◽  
Fuel Reactor ◽  
Nuclear Reactor Core ◽  
Type Fuel ◽  
Plate Type

The thermal hydraulic and neutronics coupling analysis is an important part of the high-fidelity simulation for nuclear reactor core. In this paper, a thermal hydraulic and neutronics coupling method was proposed for the plate type fuel reactor core based on the Fluent and Monte Carlo code. The coupling interface module was developed using the User Defined Function (UDF) in Fluent. The three-dimensional thermal hydraulic model and reactor core physics model were established using Fluent and Monte Carlo code for a typical plate type fuel assembly, respectively. Then, the thermal hydraulic and neutronics coupling analysis was performed using the developed coupling code. The simulation results with coupling and noncoupling analysis methods were compared to demonstrate the feasibility of coupling code, and it shows that the accuracy of the proposed coupling method is higher than that of the traditional method. Finally, the fuel assembly blockage accident was studied based on the coupling code. Under the inlet 30% blocked conditions, the maximum coolant temperature would increase around 20°C, while the maximum fuel temperature rises about 30°C. The developed coupling method provides an effective way for the plate type fuel reactor core high-fidelity analysis.

Importance of Non-Equilibrium Modelling for Compressors

2021 ◽  
Author(s):  
Robert Spencer ◽  
Pawel Przytarski ◽  
Paolo Adami ◽  
Patrick Grothe ◽  
Andrew Wheeler
Keyword(s):  
Boundary Layer ◽  
Compressor Blade ◽  
High Fidelity ◽  
Trailing Edge ◽  
Industry Standard ◽  
Sst Model ◽  
Final Equilibrium State ◽  
Standard Models ◽  
Equilibrium Region ◽  
Non Equilibrium

Abstract This paper investigates the importance of non-equilibrium boundary layer modelling for three compressor blade geometries, using RANS and high fidelity simulations. We find that capturing non-equilibrium effects in RANS is crucial to capturing the correct boundary-layer loss. This is because the production of turbulence within the non-equilibrium region affects both the loss generation in the non-equilibrium region, but also the final equilibrium state. We show that capturing the correct non-equilibrium behaviour is possible by adapting industry standard models (in this case the k-omega SST model). We show that for the range of cases studied here, non-equilibrium effects can modify the trailing-edge momentum thickness by up to 40 percent, and can change the trailing-edge shape factor from 1.8 to 2.1.

scholarly journals Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Chaitanya Talnikar ◽  
Qiqi Wang ◽  
Gregory M. Laskowski
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Adjoint Equations ◽  
High Fidelity ◽  
Trailing Edge ◽  
Eddy Simulation ◽  
Large Eddy ◽  
High Fidelity Simulations ◽  
Unsteady Adjoint ◽  
Adjoint Solutions

High-fidelity simulations, e.g., large eddy simulation (LES), are often needed for accurately predicting pressure losses due to wake mixing and boundary layer development in turbomachinery applications. An unsteady adjoint of high-fidelity simulations is useful for design optimization in such aerodynamic applications. In this paper, we present unsteady adjoint solutions using a large eddy simulation model for an inlet guide vane from von Karman Institute (VKI) using aerothermal objectives. The unsteady adjoint method is effective in capturing the gradient for a short time interval aerothermal objective, whereas the method provides diverging gradients for long time-averaged thermal objectives. As the boundary layer on the suction side near the trailing edge of the vane is turbulent, it poses a challenge for the adjoint solver. The chaotic dynamics cause the adjoint solution to diverge exponentially from the trailing edge region when solved backward in time. This results in the corruption of the sensitivities obtained from the adjoint solutions. An energy analysis of the unsteady compressible Navier–Stokes adjoint equations indicates that adding artificial viscosity to the adjoint equations can dissipate the adjoint energy while potentially maintaining the accuracy of the adjoint sensitivities. Analyzing the growth term of the adjoint energy provides a metric for identifying the regions in the flow where the adjoint term is diverging. Results for the vane obtained from simulations performed on the Titan supercomputer are demonstrated.

High-Fidelity Simulation of HIFiRE-5 Boundary-Layer Transition

AIAA Journal ◽  
2021 ◽  
pp. 1-12
Author(s):  
Matthew W. Tufts ◽  
Matthew P. Borg ◽  
Nicholas J. Bisek ◽  
Roger L. Kimmel
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Transition ◽  
High Fidelity ◽  
High Fidelity Simulation ◽  
Layer Transition

High-Fidelity Simulations of a High-Pressure Turbine Vane With End Walls: Impact of Secondary Structures and Spanwise Temperature Profiles on Losses

2021 ◽  
Author(s):  
Yaomin Zhao ◽  
Richard D. Sandberg
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Suction Side ◽  
High Fidelity ◽  
Temperature Profiles ◽  
Pressure Side ◽  
High Pressure Turbine ◽  
Vortical Structures ◽  
Wall Boundary ◽  
End Wall

Abstract In the present study, highly resolved large-eddy simulations of a VKI LS-89 high-pressure turbine (HPT) blade (T. Arts et al., 1990) with spanwise end-walls are performed at a Reynolds number of 0.57 million and an exit Mach number of 0.9. Two different spanwise temperature profiles, one uniform as baseline and one asymmetric profile extracted at the combustor exit from the public literature, are set at the inlet boundary. The high-fidelity data generated by the present cases are analyzed to investigate the end-wall secondary features, and show that the vortical structures that form near the leading edge of the vane include pressure-side and suction-side legs. While the end-wall vortical structures show no obvious effects on the time-averaged behavior of the pressure-side blade boundary layer, the suction-side structures induce counter rotating vortical structures and trigger rapid transition in the end-wall boundary layers. Furthermore, the cases with different inlet temperature profiles are directly compared, and the effects of the inflow on the aerothermal performance of the HPT vane are discussed. Based on the recently proposed entropy loss analysis (Zhao and Sandberg, GT2019-90126), we have been able to quantitatively show that the end-wall effects contribute significantly to the total loss of the turbine, with the main contributors being the extra viscous dissipation and turbulence production in the end-wall boundary layer.

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