Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia...
-
Upload
dana-cross -
Category
Documents
-
view
225 -
download
0
Transcript of Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia...
![Page 1: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/1.jpg)
Topic 1 – Internal flow
Presenter: Marco Arienti, Sandia National Laboratories
Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research and Development) is gratefully acknowledged. Sandia National
Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin
Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
![Page 2: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/2.jpg)
2
Spray C/D (4 contributors)
•Politecnico di Milano - OpenFoam: Ehsanallah Tahmasebi, Tommaso Lucchini and Gianluca D'Errico
•ANSYS-FLUENT: Saeed Jahangirian, Aleksandra Egelja-Maruszewski, and Huiying Li
•Università di Perugia - Converge:Michele Battistoni
•CMT - CavitatingFoam (OpenFoam)Pedro Martí
![Page 3: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/3.jpg)
3
Spray C Spray D
Common rail fuel injector Bosch 3-22
Fuel injector nominal diameter 0.20 mm
Nozzle K factor K=0
Nozzle shaping 5% hydroerosion
Flow with 10 MPa pressure drop 200 cc/min
Number of holes 1 (single hole)
Common rail fuel injector Bosch 3-22
Fuel injector nominal diameter 0.186 mm
Nozzle K factor K=1.5
Nozzle shaping Hydroerosion to Cd=0.86
Flow with 10 MPa pressure drop 228 cc/min
Number of holes 1 (single hole)
Axial coordinate
Radius
Wireframe of the tangentially-averaged interior wall of the sac
![Page 4: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/4.jpg)
4
Institution/Code Uni-PGConverge
ANSYS-FLUENT
PolimiOpenFOAM -cavitatingFoam
CMT OpenFOAM -cavitatingFoam
Cavitation Model Homogenous Relaxation
Zwart-Gerber-Belamri
Homogenous Equilibrium
Inclusion of turbulent viscous energy generation
Y Y Y
TurbulenceLES Dynamic sgs
RANS:SST k-ωwith compress.
RANS:SST k-ω
RANS:- k-epsilon- SST k-ω
Spatial discretization 2nd order- QUICK for void fraction - 2nd order
2nd order 2nd order
Solver PISO Steady-State Coupled PIMPLE
![Page 5: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/5.jpg)
5
Uni-PGConverge
ANSYS-FLUENT PolimiOpenFOAM -cavitatingFoam
CMT OpenFOAM -cavitatingFoam
[1] Salvador et al., Mathematical and Computer Modelling 52 2010
[1] Desantes et al., SAE l Paper 2014-01-1418
[2] Khasanshin, et al. Int. J. of Thermophysics 24(5) 2003
[1] Caudwell et al., Int. J. of Thermophysics 25(5) 2004
[2] To match Khasanshin, et al. Int. J. of Thermoph. 24(5) 2003
[3] Zwart et al. ICMF 2004
EOS models
Schmidt et al., Int. J. of Multiphase Flow (2010)
![Page 6: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/6.jpg)
6
InstitutionCode
Uni-PGConverge
ANSYS-FLUENT
PolimiOpenFOAM
CMT OpenFOAM
Inlet boundary P = 150 MPa T = 343 K
Outlet boundary P = 20 MPa T = 303 K
Fixed fully open needle configuration
![Page 7: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/7.jpg)
7
InstitutionCode
Uni-PGConverge
ANSYS-FLUENT
PolimiOpenFOAM -cavitatingFoam
CMT OpenFOAM -cavitatingFoam
Dimensionality3D, full axis-
symmetric model 2D axis-
symmetric3D
5o wedge2D axis-
symmetric
Cell Type
- Cartesian cut cells- Wall functions, y+ = 30
Hex mesh with 10 boundary layers (from 1 μm)
Hex & tets quads
Cell count (total interior and exterior) 2.5 m 20k (79k in
adapted mesh)51k (Spray C) 54k (Spray D)
Submerged N Y Y Y
![Page 8: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/8.jpg)
8
Internal flow: sharp (spray C) vs. smooth (spray D) pressure decrease
Spray C Spray D
![Page 9: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/9.jpg)
9
Without cavitation, Spray D produces a slightly longer liquid core length and a narrower cone angle
Spray C
Spray D
![Page 10: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/10.jpg)
10
This effect is recognized in new measurements of the spray width and length
*from Fredrik Westlye’s presentation
From spray boundary contrast (threshold 0.37 KL) using the diffuse backlit illumination (DBI) technique:*
![Page 11: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/11.jpg)
11
[g/s]
• CONVERGE and FLUENT-ANSYS simulations are the only that capture the increase between spray C and D
• In the aggregate, there is more variation amongst models for the same spray type than between the sprays for the same model
Comparison against measured mass flow rate
![Page 12: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/12.jpg)
12
Comparison against measured momentum
[N]
• CONVERGE and FLUENT-ANSYS simulations are the only to capture the increase between spray C and D (by a rather small margin)
![Page 13: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/13.jpg)
13
SPRAY CExperimen
t(*)Uni-PG
ConvergeANSYS-FLUENT
PolimiOpenFOAM k-ω SST
CMT OpenFOAM
k-ε
CMT OpenFOAM k-ω SST
Mass flow rate (g/s)
10.07±0.11 10.3 10.8 12.8 10.3 10.4
Momentum (N)
5.83±0.06 6.29 6.49 7.69 6.30 6.79
SPRAY DExperimen
tUni-PG
ConvergeANSYS-FLUENT
PolimiOpenFOAM k-ω SST
CMT OpenFOAM
k-ε
CMT OpenFOAM k-ω SST
Mass flow rate (g/s)
11.72±0.15 10.9 11.3 11.6 10.2 10.5
Momentum (N)
7.03±0.11 6.41 6.62 6.27 6.24 6.69
Mass flow rate and momentum values
(*) std. dev. from the CMT measurements on 5 different specimens
![Page 14: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/14.jpg)
14
Spray C: noticeable differences in boundary thickness between simulations
![Page 15: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/15.jpg)
15
Spray CSpray CSpray DSpray D
Spray D vs. spray C at the exit orifice
• Similar velocity/density profiles are obtained for spray D• Cavitation displaces mass flow toward the orifice axis in spray C
![Page 16: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/16.jpg)
16
The effect of cavitation for spray C• Note the different models’ effectiveness in generating
cavitation at the orifice’s wall liquid core boundary
![Page 17: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/17.jpg)
17
Conclusions• Relatively small variations in the amount of cavitation at the
wall result in differences of mass flow rate and momentum for spray C simulations• Even when the variation is correctly predicted, its magnitude is
underestimated
• The trend in spray penetration/width from spray C to spray D is correctly captured by the only non-submerged simulation (UniPG with Converge)• Cannot quantify agreement for lack of averaged data
• Passing pockets of vapor in the liquid core are shown in the only LES simulation (UniPG with Converge)• A frequency analysis of this feature is recommended
![Page 18: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/18.jpg)
Topic 1.2 – Spray A needle transient opening
Presenter: Marco Arienti, Sandia National Laboratories
Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research and Development) is gratefully acknowledged. Sandia National
Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin
Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
![Page 19: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/19.jpg)
19
Two of the remaining questions for Spray A from ECN3:
1.What is the exit temperature of the fuel?
2.Is the injection transient modeled realistically?
![Page 20: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/20.jpg)
20
Spray A (3 contributors)
•CMT - OpenFOAM w/ Eulerian Spray AtomizationPedro Martí
• Bosch - Cascade Technologies Edward Knudsen, Eric Doran (Bosch Research & Technology Center)
•SNL - CLSVOFMarco Arienti
![Page 21: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/21.jpg)
21
Institution:Code:
BoschCascade Technologies
CMT OpenFOAMESA
SNLCLSVOF
Equation of State for the liquid phase Peng-Robinson
Non-linear (P,T)(Payri et al., Fuel 2011)
Tait eqn. calibrated for n-dodecane; new e(P,T)
Moving mesh N N/Y (axial only) Y
InletStatic pressure increases from 0.5Pinj to Pinj at t = 0
Time-varying static pressure Constant pressure
Turbulence LES Dynamic sgs model
RANSSST k-ω No turbulence model
Inclusion of turbulent viscous energy generation? Y Y N
Spatial Discretization 2nd order 1srorder 1st / 2nd order
![Page 22: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/22.jpg)
22
Spray A ANL SNL
Liquid T [K] 363 333 343
Gas 0% O2 N2 N2
Gas T [K] 900 303 440
Back-pressure [MPa] 6 2 3
Density kg/m3 22.8 22.8 22.8
Bosch*, CMT+ SNL+
At SNL and ANL, ambient density is matched at cooler, non-vaporizing conditions. From Lyle et al. SAE 2014-01-1412
*Tfuel,intern.< 363 K+Tfuel,intern. = 343 K
Spray A reference and actual laboratory conditions
![Page 23: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/23.jpg)
23
Exit temperature predictions from ECN3
T < 0T << 0T << 0T = 0
ANLConverge
SandiaCLSVOF
UMassHRMFoam
CMTESA
IFPC3D
Incompressible Non-linear function of p,T
Const. compressibility
Non-linear function of p,T
Stiffened gas EOS
turbulent viscous energy generation
turbulent viscous energy generation
T [K]
T ≅ 0
![Page 24: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/24.jpg)
24
Contributions to T = Texit-Tinlet
•Expansion through the orifice
•Viscous energy dissipation
•Heat transfer through injector’s wall T
![Page 25: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/25.jpg)
25
Peng-Robinson Calibrated Tait
100% C12H26
Tc = 658 K c =226 kg/m3
p = 2000 bar
= 0(T ), p0 = 1 bar
Liquid phase compression
[Caudwell et al., Int. J. of Thermophysics, 2004]
![Page 26: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/26.jpg)
26
p = -1440 bar T = -22 K from calibrated Tait EOS T = 0 K from isobaric EOS T = -217 K from adiabatic p.g. EOS ( =1.4)
Isentropic expansionupper bound:
787 kg/m3
363 K 1500 bar646 kg/m3
341 K60 bar
adiabatic p.g.: = 1.4
Density[ kg/m3]
Tem
pera
ture
[K]
![Page 27: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/27.jpg)
27
Adiabatic w.Adiabatic w.
SNL results show limited temperature increasewith adiabatic walls
TL,exit = +3 K TL,exit = +18 K L,exit = 716 kg/m3 L,exit = 720 kg/m3
343 351 359 367 375 383
Temperature [K]
720 736 752 768 784 800
Density [kg/m3]Constant TW = 383 K Constant TW = 383 K
![Page 28: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/28.jpg)
28
CMT results also show small T except near the wall
Adiabatic343 K
Constant TW = 363 K
Adiabatic343 K
ConstantTW = 363 K
Temperature [K] Density [kg/m3]
![Page 29: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/29.jpg)
29
The viscous dissipation of turbulent energy is the main source of temperature increase
273 K 303 K 323 K
343 K 363 KAdiabatic
Orifice cross-sections:
![Page 30: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/30.jpg)
30
However, the opening transient displays a bulk temperature increase
• Interpretation: the fuel heats up while passing through the narrow gap between needle and injector
Simulation with moving needleTw = 383 K
• This effect disappears once the passage is fully open
![Page 31: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/31.jpg)
31
Independent study: transient and non-isothermal modeling of cavitation with GFS*
*By Salemi, McDavid, Koukouvinis, Gavaises, and Marengo, in ILASS 2015
350 K
500 K
Minimum gap: 5 m(with standard wallfunction)
Minimum cell sizex = 0.5-0.83 m
Variation of the outlet temperature in one injection cycle
Steady-state temperature field
![Page 32: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/32.jpg)
32
Conclusions on T = Texit-Tinlet
1.Expansion through the orifice:• Moderate but constant during injection• Potentially under-estimated depending on EOS
2.Viscous energy dissipation:• Potentially large but transient• Puts under scrutiny the choice of standard wall
function in micron-size gap
![Page 33: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/33.jpg)
33
The measured Rate of Injection (ROI) and Rate of Momentum (ROM) of Spray A
Diagram from SAE 2013-24-0001
![Page 34: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/34.jpg)
34
Vgas = 0.065 mm3 (1/3of the sac)Tdelay = (339-330)s = 9 s
Tdelay = 3 s (instantaneous opening)Vgas = 4 m3 (half orifice)At t < 0 the pressure in the sac is ~Pinj/2
Fully open fuel passage
Time of apparent injection
Initial conditions: injection delay as a function of partially filled sac/orifice
![Page 35: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/35.jpg)
35
Mass flow rate during opening transient*
*After removing all injection delays
![Page 36: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/36.jpg)
36
Momentum flow rate during opening transient
![Page 37: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/37.jpg)
37
Jet penetration during opening transient
![Page 38: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/38.jpg)
38
T = 353 K
Pressure [MPa]
Spee
d of
sou
nd [m
/s]
• Example: speed of sound calculation for liquid n-dodecane1. Khasanshin et al., Int. J. of Thermophysics, 24(5) 20032. Padilla-Victoria, Fluid Phase Eq. 2013
3.
A request: establish a common set of properties and reliable EOS correlations
![Page 39: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/39.jpg)
39
Backup
![Page 40: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/40.jpg)
40
++
++
Temperature [K]
Inte
rnal
Ener
gy[k
J/kg
]
300 400 500 600 700-600
-400
-200
0
200
400
600
P = 0.1 MPaP = 20 MPaP = 140 MPa
New fit:
NIST data:P = 0.1 MPaP = 20 MPaP = 140 MPaSupercriticalSupercritical
Note 3: Dependence of internal energy on pressure
[JSAE 20159137 SAE 2015-01-1853]
![Page 41: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/41.jpg)
41
Experiment set-up and reference parametersFuel n-dodecane
Inlet pressure 150 MPa
Ambient pressure 6 MPa
Fuel Temperature 363 K
Vapor sound speed (m/s) 134.59
Liquid sound speed (m/s) 1037.8
Liquid saturation density (kg/m3) 697.13
Vapor density (kg/m3) 0.071548
Saturation pressure (Pa) 12622
Liquid viscosity (Pa.s) 5.6 e-4
Vapor viscosity (Pa.s) 5.44 e-6
Thermodynamic properties from NIST web-book (for dodecane):
Cav 0.042
Re 26k/32k
![Page 42: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/42.jpg)
42
Details of mesh preparation
![Page 43: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/43.jpg)
43
MeshingNew meshing tool by Bosch-Cascade •Start from CAD surfaces•Seed domain with points•Build Voronoi diagram, connectivity
• No sliver cells at boundaries• Face normals point to cell centers• Minimal cell skew• More ‘sampling’ than hexes
Flow Domain
Voronoi Mesh
Chamber: 45 mm Long
Institution Bosch
Dimensionality 3
Cell Type 14-faced polyhedra
Cell count (total) 3x106
![Page 44: Topic 1 – Internal flow Presenter: Marco Arienti, Sandia National Laboratories Support by Sandia National Laboratories’ LDRD (Laboratory Directed Research.](https://reader034.fdocuments.us/reader034/viewer/2022050819/5697bfc11a28abf838ca4433/html5/thumbnails/44.jpg)
44
Institution CMT
Dimensionality 2
Cell Type Quad
Cell count (total) 67.4K
Geometry 12x6 mm
Institution SNL
Dimensionality 3
Cell Type Cube
Cell count (total) 7x107 to 21x107
Geometry 1.7x1.7x15.3 mm