NUMECA-NLH

20
Classic Unsteady
Cells Mesh Factor
~ 18 Mio.
~ 67 Mio.
1
3.7
03
Application to an Open Rotor Kapitelüberschrift Configuration Comparison NLH – Classic Unsteady (2)
Harmonic 2 Harmonic 1
02
Kapitelüberschrift The Non Linear Harmonic Method Method
7
NLH Method Coupling of excitations with the average values of the flow variables Benefits Fast unsteady solutions, improved steady solutions
T=100s
03
Application to an Open Rotor Kapitelüberschrift Configuration Boundary Conditions
19Leabharlann Baidu
Rotor / Stator interface between LP and IP
Rotor / Stator interface between LP/IP and fuselage
1,38 Mio.
CPU time
49500 cpuh
96 cpuh
Factor
470
1
Content
01 02 03
Motivation
The Non-Linear Harmonic Method
Application to an Open Rotor
03
Application to an Open Rotor Kapitelüberschrift Configuration Geometry Preparation
10
Import of a generic fuselage.
Import of a generic pylon profile.
Blade definition by sections for LP and IP
Import of naczelle as meridonial kontur
03
Application to an Open Rotor Kapitelüberschrift Configuration Numerical Grid
BPF/Harmonic 1st 1st 2nd 1st 2nd 3rd 1st/1st/1st 1st/1st/1st 3rd 4th 1st/1st/2nd 2nd/2nd 5th 1st/1st/2nd Row IP LP IP LP+IP LP IP IP+LP+IP LP+LP+IP LP IP LP+IP+IP LP+IP IP LP+IP+LP Frequency 114.57 Hz 156.72 Hz 229.14 Hz 271.29 Hz 313.14 Hz 343.71 Hz 385.86 Hz 428.01 Hz 470.16 Hz 458.28 Hz 500.43 Hz 542.60 Hz 572.58 Hz 585.91 Hz
02
Kapitelüberschrift The Non Linear Harmonic Method Method
6
NLH Method A wake is transferred to a downstream row and generates harmonic motion?
time
Rotation
Non-Linear Harmonic Mesh
21
Classic Unsteady
Time steps CPU / time step (12 cores) CPU time
1000 780 s
360*20*2*1306 296 s
9 days
64.429 days
Factor
1
7.159
03
Application to an Open Rotor Kapitelüberschrift Configuration Possible Frequencies
2010
Workshop: 15 Jahre NGV Dresden
Unsteady CFD Calculations on an Open Rotor Configuration
Content
01 02 03
Motivation
The Non-Linear Harmonic Method
Application to an Open Rotor
17
Outlet (air intake): =0 =0 =1
Mass flow = 20 kg/s
Inlet (core outlet): |Vr|/|V| = |Vt|/|V| = |Vz|/|V| = T 0 0 1
= 900 K
Mass flow = 20.5 kg/s
03
Application to an Open Rotor Kapitelüberschrift Configuration
12
Very fine mesh resolution
3D Mesh
03
Application to an Open Rotor Kapitelüberschrift Configuration Numerical Grid 3D Mesh
13
Mesh at air intake
Mesh on nacelle (rear view)
Application to an Open Rotor Kapitelüberschrift Configuration Probe 1 – Static Pressure Fluctuation Detail
Inlet: |Vr|/|V| = |Vt|/|V| = |Vz|/|V| = Tt Pt 0 0 1 = 326.13 K =147380 Pa
Rotor/Stator-Interfaces: 1D Non Reflecting Mixing Plane
Domain Periodicity LP: 12 RPM: 783.6 min-1
Domain Periodicity IP: 9 RPM: -763.8 min-1
03
|Vr|/|V| |Vt|/|V| |Vz|/|V|
Application to an Open Rotor Kapitelüberschrift Configuration Boundary Conditions
03
Application to an Open Rotor Kapitelüberschrift Configuration Probe 1 – Static Pressure Fluctuation
24
1
Signal of static pressure for 5 full cycles.
03
Full Unsteady NLH – 3 Freq
8d on 64 cpu
3h on 8 cpu
02
Kapitelüberschrift The Non Linear Harmonic Method Example
Classic Unsteady
8
Non-Linear Harmonic
Mesh
40 Mio.
Content
01 02 03
Motivation
The Non-Linear Harmonic Method
Application to an Open Rotor
02
Kapitelüberschrift The Non Linear Harmonic Method Overview
5
Non Linear Harmonic (NLH) Method New method to perform fast and accurate unsteady simulations CPU & RAM Dramatic reduction compared to classical unsteady methods.
Rotor / Stator interface between LP and pylon
03
Application to an Open Rotor Kapitelüberschrift Configuration Comparison NLH – Classic Unsteady (1)
Non-Linear Harmonic Mesh
03
Application to an Open Rotor Kapitelüberschrift Configuration Numerical Grid 3D Mesh
14
3D Mesh (rear view)
03
Application to an Open Rotor Kapitelüberschrift Configuration Numerical Grid 3D Mesh
01
Kapitelüberschrift Motivation Why Counter Rotating Open Rotor?
Why Counter Rotating Open Rotor? Significant improvements in SFC possible
3
Why unsteady CFD? Rotor-Rotor interaction creates pressure fluctuations and high acoustic loads Why the Non Linear Harmonic Method? Other unsteady methods hardly applicable
16
Flow & Physics: Mathematical Model: Turbulent Navier Stokes Turbulence Model: Spalart Almaras Air (perfect gas)
Outlet: Pressure imposed Averaged static pressure P = 101300 Pa
Number of blocks Topology Spanwise Total # of points
8 HHOHH 133 ~3 Mio.
7 HHOHH 133 ~2 Mio.
5 HHOHH 89 ~5 Mio.
03
Application to an Open Rotor Kapitelüberschrift Configuration Numerical Grid 3D Mesh
Periodic Signal: General Considerations
18
System: R1-R2-S1: f1 = 783,6rpm/60 = 13,06Hz f2 = 768,3rpm/60 = 12,73Hz
Periodic signal: T = N1/f1 = N2/f2 N1/N2 = f1/f2 = 1306/1273 (largest common divider:1) R1: 1306 revs, R2: 1273 revs
15
Mesh at core outlet
Mesh at trailing edge of pylon @ fuselage
03
Fluid:
Application to an Open Rotor Kapitelüberschrift Configuration Boundary Conditions
Numerical Grid Type Total # of points Total # of blocks Structured, multi-block ~18 Mio. 133
11
LP (row 1)
IP (row 2)
Pylon
Fuselage, airintake, core outlet & nonaxis-symetric parts 113 H ~8 Mio.
22
LP
IP
03
Application to an Open Rotor Kapitelüberschrift Configuration Probing Locations
23
10 11 12 3 6 9 2 5 8 1 4 7
Probe location (Frontal view)
Probe location (From top)