Uncertainty and sensitivity analysis of flow parameters for transition models on hypersonic flows

“…Since the physical experiment was performed in a free-piston shock tunnel [33], the freestream turbulence intensity, Tu ∞ , is chosen to meet the same shock-tunnel condition. Two studies have performed similar experiments in the same type of shock tunnel, where the freestream flow is around Mach 6 [36,37]. Based on those reports, the Tu ∞ value is set to 0.4% here.…”

Section: Eilmer and Numerical Plate Modelmentioning

confidence: 99%

“…However, the similar hypersonic flow condition where Tu ∞ equals 0.4% is also used in two papers. One is in simulation with the γ − Re θt model and the k − ω − γ model [37]. Another one is tested with a one-equation γ model [40].…”

Section: Tu ∞ and γ Bc In Sa-bcm Modelmentioning

confidence: 99%

Simulations of Hypersonic Boundary-Layer Transition over a Flat Plate with the Spalart-Allmaras One-Equation BCM Transitional Model

Chen

Gibbons

2022

Mathematics

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Transitional flow has a significant impact on vehicles operating at supersonic and hypersonic speeds. An economic way to simulate this problem is to use computational fluid dynamics (CFD) codes. However, not all CFD codes can solve transitional flows. This paper examines the ability of the Spalart–Allmaras one-equation BCM (SA-BCM) transitional model to solve hypersonic transitional flow, implemented in the open-source CFD code Eilmer. Its performance is validated via existing wind tunnel data. Eight different hypersonic flow conditions are applied. A flat plate model is built for the numerical tests. The results indicate that the existing SA-BCM model is sensitive to the freestream turbulence intensity and the grid size. It is not accurate in all the test cases, though the transitional length can be matched by tuning the freestream intensity. This is likely due to the intermittency term of the SA-BCM model not being appropriately calibrated for high-velocity flow, though if the model can be recalibrated it may be able to solve the general high-velocity flows. Although the current SA-BCM model is only accurate under certain flow conditions after one calibration process, it remains attractive to CFD applications. As a one-equation model, the SA-BCM model runs much faster than multiple-equation flow models.

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“…The variance analysis method is normally utilized for work optimization [ 24 , 25 ]. The Monte Carlo method commonly requires a substantial number of samples, thus leading to high run costs [ 26 ]. In recent studies, surrogate models building an exact relation between model inputs and responses are given sufficient attention, including the Gaussian process regression method [ 27 ], the Bayesian model averaging method [ 28 ] and polynomial chaos expansion methods [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

Sensitivity analysis of heat and mass transfer at working face in high-temperature mine

Zhou,

Zhang,

Zhang

2024

PLoS ONE

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Thermal damage from heat sources severely affects the safety of deep mine production. Heat and mass transfer between heat sources and airflow leads to the increase of the airflow temperature (AFT), moisture content of airflow (AFMC) and relative humidity of airflow (AFRH). This study aims to quantify uncertainty contributions of the working face parameters on AFT, AFMC and AFRH and find their main contributors. The flow, geometric and physical parameters are chosen as uncertainty sources. Subsequently, Sobol indices are obtained using the point-collocation non-intrusive polynomial chaos method, denoting the sensitivity of each input parameter. It was found that the inflow wind temperature and the wind velocity are two top factors influencing AFT and AFMC, while relative humidity of inflow wind and the wind velocity are two top factors influencing AFRH. In the single factor analysis, the uncertainty contributions of the inflow wind temperature on AFT and AFMC, and relative humidity of inflow wind on AFRH can exceed 0.7, which is higher than those of the wind velocity. The geometric parameters of the working face, namely the length, width and height, and ventilation time are also significant quantities influencing AFT, AFMC and AFRH. Compared to AFT and AFMC, two other significant quantities influencing AFRH are the thermal conductivity of coal and the original temperature of the rock.

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Uncertainty and sensitivity analysis of flow parameters for transition models on hypersonic flows

Cited by 22 publications

References 37 publications

Impact of asymmetrical heating on the uncertainty propagation of flow parameters on wall heat transfers in solar receivers

Impact of asymmetrical heating on the uncertainty propagation of flow parameters on wall heat transfers in solar receivers

Simulations of Hypersonic Boundary-Layer Transition over a Flat Plate with the Spalart-Allmaras One-Equation BCM Transitional Model

Sensitivity analysis of heat and mass transfer at working face in high-temperature mine

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