Development of Statistical Core Thermal Design Methodology Using a Modified Latin Hypercube Sampling Method

1991 ◽  
Vol 94 (3) ◽  
pp. 407-415 ◽  
Author(s):  
Seung-Hyuk Lee ◽  
Hyun-Koon Kim ◽  
Sang-Ryeol Park ◽  
Soon-Heung Chang
Keyword(s):  
Design Methodology ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Thermal Design ◽  
Latin Hypercube

Uncertainty Quantification of Turbulence Model Coefficients via Latin Hypercube Sampling Method

2010 ◽  
Author(s):  
Matthew C. Dunn ◽  
Babak Shotorban ◽  
Abdelkader Frendi
Keyword(s):  
Uncertainty Quantification ◽  
Turbulent Flows ◽  
Turbulence Model ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Recirculation Region ◽  
Free Shear Layer ◽  
Latin Hypercube ◽  
Reattachment Point ◽  
Turbulent Dissipation

This paper is concerned with the propagation of uncertainties in the values of turbulence model coefficients and parameters in turbulent flows. These coefficients and parameters are determined from experiments performed on elementary flows and they are subject to uncertainty. The widely used k–ε turbulence model is considered. It consists of model transport equations for the turbulence kinetic energy and rate of turbulent dissipation. Both equations involve various model coefficients about which adequate knowledge is assumed known in the form of probability density functions. The study is carried out for the flow over a 2D backward-facing step configuration. The Latin Hypercube Sampling method is employed for the uncertainty quantification purposes as it requires a smaller number of samples compared to the conventional Monte-Carlo method. The mean values are reported for the flow output parameters of interest along with their associated uncertainties. The results show that model coefficient variability has significant effects on the streamwise velocity component in the recirculation region near the reattachment point and turbulence intensity along the free shear layer. The reattachment point location, pressure, and wall shear are also significantly affected.

A Probabilistic Safety Assessment Method Based on Latin Hypercube Sampling Method

2015 ◽  
Vol 757 ◽  
pp. 159-163
Author(s):  
Ying Juan Yue ◽  
Fei Chen ◽  
Hong Li ◽  
Hai Xia Du ◽  
Xiao Jun Du
Keyword(s):  
Change Process ◽  
Safety Assessment ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Assessment Method ◽  
Probabilistic Assessment ◽  
Latin Hypercube ◽  
Probabilistic Safety Assessment ◽  
Failure Assessment ◽  
Probabilistic Safety

Based on the shortcomings of traditional probabilistic assessment methods, an improved probabilistic safety assessment method was proposed, which used Latin hypercube sampling, considered the change process about fatigue crack propagation, as well as the effect of random variables on the failure assessment curve. The paper also analyzed the specific example with this method. The results showed that this method was simpler and more effective, which had some value of applications in engineering.

Research on the Micro-Mechanical State at Tip of Environmentally Assisted Cracking Based on Latin Hypercube Sampling Method

2019 ◽  
Vol 795 ◽  
pp. 74-78
Author(s):  
Kuan Zhao ◽  
He Xue ◽  
Ling Yan Zhao
Keyword(s):  
Oxide Film ◽  
Material Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Primary Circuit ◽  
Mechanical State ◽  
Latin Hypercube ◽  
Environmentally Assisted Cracking

Environmentally assisted cracking (EAC) of nickel-based alloys is one of the most significant potential safety hazards in the primary circuit of nuclear power plants. To understand the influence of randomness on micro-mechanical state at tip of EAC, Latin hypercube sampling method is applied to analyze the uncertainty of stress-strain in the oxide film at the EAC tip considering the uncertainties of load and material properties of base metal and oxide film. Meanwhile, to improve the efficiency of numerical analysis, MATLAB is employed in the secondary development for ABAQUS. With the help of finite element numerical simulation and Latin hypercube sampling method, the uncertainty of mechanical properties at tip of EAC in one-inch compact tension specimen is simulated and analyzed in this study. The results show that the randomness of material properties and load markedly affect the uncertainty of micro-mechanical state. Among the variables, The randomness of load has the greatest influence on uncertainty of strain, and Poisson`s ratio of oxide film is the smallest effect.

Uncertainty Quantification of Turbulence Model Coefficients via Latin Hypercube Sampling Method

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Matthew C. Dunn ◽  
Babak Shotorban ◽  
Abdelkader Frendi
Keyword(s):  
Uncertainty Quantification ◽  
Turbulent Flows ◽  
Turbulence Model ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Recirculation Region ◽  
Free Shear Layer ◽  
Latin Hypercube ◽  
Reattachment Point ◽  
Mean Velocity

The article is concerned with the propagation of uncertainties in the values of turbulence model coefficients and parameters in turbulent flows. These coefficients and parameters are obtained through experiments performed on elementary flows, and they are subject to uncertainty. In this work, the widely used k-ɛ turbulence model is considered. It consists of model transport equations for the turbulence kinetic energy and the rate of turbulent dissipation. Both equations involve various model coefficients about which adequate knowledge is assumed known in the form of probability density functions. The study is carried out for a flow over a 2D backward-facing step configuration. The Latin Hypercube Sampling method is employed for the uncertainty quantification purposes as it requires a smaller number of samples compared to the conventional Monte Carlo method. The mean values are reported for the flow output parameters of interest along with their associated uncertainties. The results show that model coefficient variability has significant effects on the streamwise mean velocity in the recirculation region near the reattachment point and turbulence intensity along the free shear layer. The reattachment point location, pressure, and wall shear are also significantly influenced by the uncertainties of the coefficients.

A STOCHASTIC FINITE ELEMENT ANALYSIS BASED ON UNIFORM SAMPLING METHOD

2008 ◽  
Vol 07 (01) ◽  
pp. 69-73
Author(s):  
GANG LEI ◽  
LINQING LIAO
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Stochastic Finite Element ◽  
Latin Hypercube ◽  
Element Analysis ◽  
Mean Values ◽  
Uniform Sampling ◽  
Stochastic Finite Element Analysis

Stochastic finite element method is the main analysis method of complicated stochastic structure, and it is mainly applied to the Monte Carlo simulation method. Its sampling method is commonly called the Latin Hypercube sampling method. But for stochastic finite element analysis, and if level numbers for sampling are too many, sampling numbers will be difficult for most engineering purposes. In this paper, uniform sampling method is applied. Calculating examples with different factors and levels are compared with calculating examples in which Latin Hypercube sampling method is applied. Calculating examples show that when sampling numbers by uniform sampling technique is obviously fewer than sampling numbers by Latin Hypercube, mean values and standard deviations of displacements, stresses of node by the two sampling methods are almost completely identical. Uniform samplings for stochastic finite element analysis have good computing efficiency, and have certain applied perspectives.

Sign in / Sign up

Export Citation Format

Share Document