Hypersonic Flow Heat Transfer Prediction Using Single Equation Turbulence Models

2000 ◽  
Vol 123 (1) ◽  
pp. 65-69 ◽  
Author(s):  
U. Goldberg
Keyword(s):  
Heat Transfer ◽  
Hypersonic Flow ◽  
High Speed ◽  
Turbulence Models ◽  
Single Equation ◽  
Test Case ◽  
Flow Heat ◽  
High Speed Flows

Three single equation turbulence models were applied to a test case of a Mach 9 flow over a 38 deg ramp. None of the models have been optimized to high-speed flows. Results indicate that the Rt closure outperforms both the Spalart-Allmaras and Menter’s models in predicting this flow. Since the Rt model’s formulation is also topography-parameter-free, it seems to be the best choice for use in hypersonic heat transfer prediction within the single equation closure family.

Large Eddy Simulation of the Heat Transfer Due to Swirling and Non-Swirling Jet Impingement

2008 ◽  
Author(s):  
Naseem Uddin ◽  
S. O. Neumann ◽  
B. Weigand
Keyword(s):  
Heat Transfer ◽  
Turbulence Models ◽  
Jet Impingement ◽  
Impinging Jet ◽  
Test Case ◽  
Complex Flow ◽  
Free Jet ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Target Wall

Turbulent impinging jet is a complex flow phenomenon involving free jet, impingement and subsequent wall jet development zones; this makes it a difficult test case for the evaluation of new turbulence models. The complexity of the jet impingement can be further amplified by the addition of the swirl. In this paper, results of Large Eddy Simulations (LES) of swirling and non-swirling impinging jet are presented. The Reynolds number of the jet based on bulk axial velocity is 23000 and target-to-wall distance (H/D) is two. The Swirl numbers (S) of the jet are 0,0.2, 0.47. In swirling jets, the heat transfer at the geometric stagnation zone deteriorates due to the formation of conical recirculation zone. It is found numerically that the addition of swirl does not give any improvement for the over all heat transfer at the target wall. The LES predictions are validated by available experimental data.

Numerical Investigation of Flow and Heat Transfer Characteristics for Attached and Separated Low-Pr Flows

2019 ◽  
Author(s):  
S. Bhushan ◽  
M. Elmellouki ◽  
W. D. Jock ◽  
D. K. Walters ◽  
J. K. Lai ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Channel Flow ◽  
Flow Separation ◽  
Turbulent Diffusion ◽  
Plane Channel ◽  
Turbulence Models ◽  
Test Case ◽  
Convective Conditions ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Abstract This study performs a comprehensive analysis of the effect of flow separation and reattachment, convective conditions and Pr to understand their effect on heat transfer characteristics and the predictive capability of low- and hig-fidelity turbulence models are assessed. To achieve the objective DNS is performed for plane channel flow at Reτ = 640, Pr = 0.71 and 0.025 involving mixed forced and natural convection condition, and RANS, hybrid RANS/LES, and LES calculations are performed for backward backing step with expansion ratio 1.5, Pr = 0.71 and 0.0088 and Ri = 0 and 0.338. Channel flow simulations reveal that the convective conditions affect the near-wall turbulent structures and thermal diffusion more significantly in high-Re flows that in low-Re flows. Thus, the generated DNS database provides a challenging test case for turbulence model validation. For backward facing step case, all the turbulence models predict the overall flow characteristics, and Ri = 0 case is a more challenging validation test case than Ri = 0.338, as the former involves complex turbulent diffusion, whereas the latter is dominated by large scale buoyancy driven convection. Results show that well resolved PANS and LES predictions can help in improve understanding of turbulent diffusion under complex convection and flow separation/ reattachment regimes. RANS results are also quite encouraging and indicates that they may represent a reasonable compromise between computational expense and accuracy for cases in which high resolution simulations are not feasible.

Heat Transfer Analysis of Exhaust Manifold with Water Jacket of a High Speed Gasoline Based on FSI

2014 ◽  
Vol 532 ◽  
pp. 439-442
Author(s):  
Jing Yang ◽  
Zhen Lu ◽  
Ke Li ◽  
Yi Wang
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Gasoline Engine ◽  
Mutual Effect ◽  
Turbulence Models ◽  
Flow Distribution ◽  
Heat Transfer Analysis ◽  
Exhaust Manifold ◽  
Complex Flow ◽  
Water Jacket

The fluid-structure interaction (FSI) method is employed to analyze heat transfer of a exhaust manifold with a water jacket. Three different turbulence models are valued to predict their spheres of application. The mutual effect on complex flow distribution and heat transfer with and without transition is also considered respectively. The results show that reasonable turbulence model and transition will contribute to a better numerical precision of temperature distribution. Considering transition will have a impact on the design of novel exhaust manifold of high speed gasoline engine. In addition, numerical results can be referred to improve the structure.

A Methodical Assessment of two-equation Turbulence Models for High-Speed flows

2021 ◽  
Author(s):  
Chitrarth Prasad ◽  
Matthew J. Schwartz ◽  
Datta Gaitonde
Keyword(s):  
High Speed ◽  
Turbulence Models ◽  
High Speed Flows
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