Guidelines for validation experiments Oberkampf and Roy provide guidelines for validation...
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Guidelines for validation experiments Oberkampf and Roy provide guidelines for validation experiments This lecture deals with their applications to the
Guidelines for validation experiments Oberkampf and Roy provide
guidelines for validation experiments This lecture deals with their
applications to the Paper helicopter CCMT shock tube validation of
Rocflu
Slide 3
CCMT | 2 Explosive solid particle dispersal Target three
dimensional dispersal phenomenon -Explosive processes influence
dynamics of densely packed particles -Predicting particle dynamics
with a simulation
Slide 4
CCMT | 3 Validation of Shock Tube Simulation Validation of the
models for shock-particle interactions Experimental Data Shock Tube
Simulation Validation
Slide 5
I: Joint design Guideline 1: A validation experiment should be
jointly designed by experimentalists, model developers, and code
users working closely together throughout the program, from
inception to documentation with complete candor about the strength
and weaknesses of each approach.
Slide 6
History of processes Experiments always precede some of the
modeling. Validation is intended to check whether the model only
works as a curve fit or does it have predictive capability. For
shock tube V&V team acts as bridge. How did you wear the
different hats of analysts, code developers and experimentalists
for helicopter project? What is the validation part of the paper
helicopter project?
Slide 7
CCMT | 6 Prediction Metrics Prediction Metrics: The locations
of the particle curtain edges at upstream and downstream What are
the alternatives? Curtain thickness after impact Before impact
After impact
Slide 8
What should be measured? Guideline 2: A validation experiment
should be designed to capture the essential physics of interest,
and measure all relevant physical modeling data, initial and
boundary conditions, and system excitation information required by
the model. For the shock tube experiment the essential physics is
the interaction of shock and particles. What is the essential
physics for helicopter? What else would be worthwhile
measuring?
Slide 9
Synergism Guideline 3: A validation experiment should try to
emphasize the inherent synergism that is attainable between
computational and experimental approaches. Example: Use simple
configuration to reveal test deficiencies (e.g. flow without
particles) Example: Use simulation to decide on sensor placement.
Examples from helicopter project?
Slide 10
Independence Guideline 4: Although the experimental design
should be developed cooperatively, independence must be maintained
in obtaining the computational and experimental system response
results. Blind test prediction is important! Why?
Slide 11
Hierarchy of measurements Guideline 5: Experimental
measurements should be made of a hierarchy of system response
quantities, for example from globally integrated quantities to
local quantities. For shock tube experiment, local quantities
include pressures and local volume fractions. What are local and
global quantities for helicopter measurements?
Slide 12
Uncertainty Guideline 6: The experimental design should be
constructed to analyze and estimate the components of random
(precision) and systematic (bias) experimental uncertainties. How
do you determine the bias in the helicopter experiment?