Interpretation of Validation Results Following ASME V&V20-2009

Author(s):  
Patrick J. Roache

Suggestions are made for modification and extension of the methodology and interpretations of ASME V&V 20-2009, Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer. A more conservative aggregation of numerical uncertainty into the total validation uncertainty is recommended. A precise provisional demarcation for accepting the validation comparison error as an estimate of model error is proposed. For the situation where the validation exercise results in large total validation uncertainty, a more easily evaluated estimated bound on model error is recommended. Explicit distinctions between quality of the model and quality of the validation exercise are discussed. Extending the domain of validation for applications is treated by interpolating/extrapolating model error and total validation uncertainty, and adding uncertainty from the new simulation at the application point. Model form uncertainty and epistemic uncertainties in general, while sometimes important in model applications, are argued to not be important issues in validation.

2005 ◽  
Author(s):  
Hugh W. Coleman

An approach to verification and validation (V&V) using experimental uncertainty analysis concepts to quantify the result of a validation effort is discussed. This is the approach to V&V being drafted by the American Society of Mechanical Engineers (ASME) Performance Test Code Committee, PTC 61: Verification and Validation in Computational Fluid Dynamics and Heat Transfer. The charter of the committee is “Provides procedures for quantifying the accuracy of modeling and simulation in computational fluid dynamics and heat transfer.” The committee is initially focusing its efforts on drafting a standard for V&V in computational fluid dynamics and heat transfer based on the concepts and methods of experimental uncertainty analysis. This will leverage the decades of effort in the community of experimentalists that resulted in the ASME Standard PTC 19.1 “Test Uncertainty” and the ISO international standard “Guide to the Expression of Uncertainty in Measurement.”


Author(s):  
Christopher J. Freitas

ASME Codes and Standards created a new Performance Test Code Committee in May of 2004, whose primary focus is on the formalization of an approach to the process for verification and validation in computational fluid dynamics and heat transfer. PTC-61 has as its charter to provide “procedures for quantifying the accuracy of modeling and simulation in computational fluid dynamics and heat transfer.” The committee is initially focusing on an approach based on the concepts and methods of experimental uncertainty analysis. This will leverage the decades of development in the community of experimentalists that resulted in the ASME Standard PTC 19.1 “Test Uncertainty” and the ISO international standard “Guide to the Expression of Uncertainty in Measurement.” This paper provides a brief summary of the status of the PTC-61 effort to develop a standard for V&V.


2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.


Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  

Combustor liner of present gas turbine engines is subjected to high thermal loads as it surrounds high temperature combustion reactants and is hence facing the related radiative load. This generally produces high thermal stress levels on the liner, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the flame tube life span and to ensure safe operations. The present study aims at investigating the aerothermal behavior of a GE Dry Low NOx (DLN1) class flame tube and in particular at evaluating working metal temperatures of the liner in relation to the flow and heat transfer state inside and outside the combustion chamber. Three different operating conditions have been accounted for (i.e., lean–lean partial load, premixed full load, and primary load) to determine the amount of heat transfer from the gas to the liner by means of computational fluid dynamics (CFD). The numerical predictions have been compared to experimental measurements of metal temperature showing a good agreement between CFD and experiments.


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