efc topic 4.3 benchmarking : comparisons, analysis, and validation
DESCRIPTION
EFC Topic 4.3 Benchmarking : comparisons, analysis, and validation . Objectives Topic 4.3 Exposition of methods & metrics being used to assess simulation equivalency & efficacy of measured flow & combustion. Define ECN 3.X Topics, 2014-2015 - Identify what is needed. - PowerPoint PPT PresentationTRANSCRIPT
Topic 4: Engine, Flow, & Combustion
1April 5, 2014
ECN 3.0EFC Topic 4.3 Benchmarking:
comparisons, analysis, and validation
Objectives Topic 4.3
Exposition of methods & metricsbeing used to assess
simulation equivalency & efficacy ofmeasured flow & combustion
Define ECN 3.X Topics, 2014-2015- Identify what is needed.- Identify action.
Topic 4: Engine, Flow, & Combustion
2April 5, 2014
ECN 3.0EFC Topic 4.3 Benchmarking: comparisons, analysis, and validation
Presented by Dave Reuss
Sources of contributions to EFC:
Tech. Univ. Darmstadt; Brian Peterson, [email protected]
IFP Energie Nouvelles; Cecile Pera, [email protected]
Penn. State Univ; Dan Haworth, [email protected]
Univ. Michigan; David Reuss, [email protected], Volker Sick, [email protected]
Politecnico di Milano;Tommaso Lucchini, [email protected]
Univ. Duisburg-Essen; Sebastian Kaiser, [email protected]
General Motors R&D; Xiaofeng Yang, [email protected], Tang-Wei Kuo, [email protected]
Topic 4: Engine, Flow, & Combustion
3April 5, 2014
ECN 3.0
4.3.1. Global engine operating conditions
4.3.2. In-cylinder flow characterization
4.3.3. Simulated to measured combustion modeling validation
4.3. Benchmarking: comparisons, analysis, and validation
ECN 3.X 2014-2015 Efforts: Interdependency requires parallel efforts.
Rational flow CCV metrics require knowledge of what flow parameters best correlate with fuel-mixing and combustion CCV
Ultimately, all detailed (small time and space scale) simulation quantities must predict volume-average/global measure (work and engine-out emissions)
Topic 4: Engine, Flow, & Combustion
4April 5, 2014
ECN 3.0
4.3.1. Global Engine Metrics
Topic 4: Engine, Flow, & Combustion
5April 5, 2014
ECN 3.04.3.1. Global engine operating conditions
4.3.1.1. In-cylinder 0-D & Global Metrics
TCC-III
P_cyl Pegging
ECN 3.X Topic option:Document
precision & accuracy formechanical & pressure
test-to-test & CCV.
Location Peak Pressure
Topic 4: Engine, Flow, & Combustion
6April 5, 2014
ECN 3.04.3.1. Global engine operating conditions
4.3.1.1. In-cylinder 0-D & Global Metrics
ECN 3.X Topic option:- Identify useful volume- & plane-averaged metrics.- Quantify flow metrics & values for simulation effectiveness.
KE @
Fie
ld o
f Vie
w
TCC
Milano
Topic 4: Engine, Flow, & Combustion
7April 5, 2014
ECN 3.04.3.1.2. Intake & Exhaust Systems 1-D quantities
ECN 3.X Topic options:- Quantify effect of P_Intk_Port CCV on trapped mass & flow.- Quantify simulation noise precision and accuracy.
TCC-III
PIntakePort Discrepancy,
(simulation – measurement)
CoV,
%
Disc
repa
ncy,
%
Measurement Noise
LES CCV
Topic 4: Engine, Flow, & Combustion
8April 5, 2014
ECN 3.0
ECN 3.X Topic options:- Quantify impact of intake-port
1-D pressure & 3-D velocityon in-cylinder CCV.
4.3.1. Global engine operating conditions4.3.1.2. Intake & Exhaust Systems 1-D quantities
INTAKE
Inta
ke p
ipe
velo
city
[m/s
]
SGEmac
-200 CAD
LES: 25 cycles
PIV: 200 cycles
Trap
ped
Mas
s
Mean Pintake
Topic 4: Engine, Flow, & Combustion
9April 5, 2014
ECN 3.0
4.3.2. In-cylinder flow characterization
Topic 4: Engine, Flow, & Combustion
10April 5, 2014
ECN 3.0
SGEmac
ECN 3.X Topic option:Identify methods and metrics to quantitatively assess equivalency of simulated & measured velocity and momentum dissipation.
4.3.2. Simulated-to-Measured Flow characterization4.3.2.1. Statistical Methods
SIDI TUD
𝝏𝒖 /𝝏 𝒙
next step
Resolution dependence
Model dependences
Topic 4: Engine, Flow, & Combustion
11April 5, 2014
ECN 3.04.3.2. Simulated-to-Measured Flow characterization
4.3.2.1. Statistical Methods4.3.2.1.1. phase-average and standard deviation
SIDI TUD
Measured Ens. AveLES Ens. Ave. Ens,. Std. Dev.
Ensemble Average & Standard Deviation (CCV) of PIV & LES velocity are equivalent metrics.
ECN 3.X Topic option:Identify rational measurements to
characterize RANS “turbulence”
TCC, RANS
Topic 4: Engine, Flow, & Combustion
12April 5, 2014
ECN 3.0
Max velocity
Velocity noise
4.3.2. Simulated-to-Measured Flow characterization4.3.2.1. Statistical Methods
4.3.2.1.2. CCV vs. turbulence vs. noise
ECN 3.X Topic option:- Standards exist to quantify measurement noise. - How are simulation noise & uncertainty quantified?
PIV dynamic range
PIV interrogation % first choices
PIV interrogation quality
Crankangle
Simulation Noise
?
Topic 4: Engine, Flow, & Combustion
13April 5, 2014
ECN 3.04.3.2. Simulated-to-Measured Flow characterization
4.3.2.2. Proper Orthogonal Decomposition,
Snapshots sampled @ one CA, all cycles
POD creates multi-dimensional “empirical” basis functions.
Modes created based on flow
- high KE (V2, or I2)
- and/or repeatable.
Phase-dependent POD
Mode 1 mid intake stroke
- Eigen values capture KE.
- Can be used for CCV of Modes
cycle #
KE,
m2 /
s2
TCC- I
Topic 4: Engine, Flow, & Combustion
14April 5, 2014
ECN 3.0
TCC
4.3.2.2. Proper Orthogonal Decomposition,
Velocity snapshots 1. sampled @ all CA, all cycles2. mapped to single grid 3. normalized to KE of individual snapshot
POD creates single set of modes applicable to• all CA, • all cycles.
Normalized KE creates modes based on• normalized velocity and• intra-cycle persistence (cycle similarity)
Phase-invariant POD
Eigenvalue captures intra-cycle variability flow similarity
CCV
crank angle
Coeffi
cien
ts
Mode 2
Mode 1
Topic 4: Engine, Flow, & Combustion
15April 5, 2014
ECN 3.04.3.2. Simulated-to-Measured Flow characterization
ECN 3.X Topic option:POD is not universally or extensively used as a metric. Identify acceptable methods and standards of POD application.
Combine Measured & LES snapshots + Phase-invariant POD single set of POD Modes.
crank angle
Coeffi
cien
ts
LESPIV
Coefficients provide metric for direct comparison of measured vs simulated Intra-cycle and Inter-cycle equivalence.
Topic 4: Engine, Flow, & Combustion
16April 5, 2014
ECN 3.04.3.2. Simulated-to-Measured Flow characterization
4.3.2.8. Simulation efficacy of scalar mixing.
ECN 3.X Topic option:
Efficacy of simulations onone- & two-phase mixing,
especially sub-grid.
End ofhydrogen injection
Experiment Simulation
H2 mole
fraction
H2ICE
Topic 4: Engine, Flow, & Combustion
17April 5, 2014
ECN 3.0
4.3.3. Combustion-Modeling validation
Topic 4: Engine, Flow, & Combustion
18April 5, 2014
ECN 3.0
ECN 3.X Topic option:- Create defined methods for computing work (IMEP) and
Apparent Heat Release, AHR.- Establish standard of accepted equivalence between
measured and simulated AHR.
4.3.3. Combustion modeling validation4.3.3.1. Global heat release
SGEmac
I
Topic 4: Engine, Flow, & Combustion
19April 5, 2014
ECN 3.04.3.2. Combustion modeling validation
4.3.3.2. Ignition and early flame development.
PDF of burned gas
3-D projection
OH PLIF, probability of flame
Chemiluminescence,Single cycle
SGEmac
Single-cycleMie-scattering PDF of burn-gas
SIDI TUD
PDF of burned gas2-D plane
Topic 4: Engine, Flow, & Combustion
20April 5, 2014
ECN 3.04.3.2. Combustion modeling validation
4.3.3.2. Ignition and early flame development.
ECN 3.X Topic option:Identify optical metrics applicable to both measured & simulated data to define equivalency during early burning ( burned mass fraction < 20%).
0.20
0.15
0.10
0.05
0.00-5 0 5 10 15
ST (m/s)
(ST)
SIDI TUD
Topic 4: Engine, Flow, & Combustion
21April 5, 2014
ECN 3.0
ECN 3.X Topic option:What is needed?What experiments are possible ?
4.3.2. Combustion modeling validation4.3.3.2. Fully Developed turbulent flame
Turbulent-combustion of late-burned mass Compressed scales
Dissipation
Near-wall
Poor optical access (esp. SC SIDI with a bowl)