Multi-objective optimization of a
centrifugal compressor for turbocharging
Johannes RatzGas Turbines and Aerospace Propulsion
TU Darmstadt
Source:
MTU Friedrichshafen GmbH
Contents
2Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
Optimization-Workflow
Results
Introduction
3Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
Source:
MTU Friedrichshafen GmbH
Introduction
4Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
Source:
MTU Friedrichshafen GmbH
Turbocharger
Introduction
5Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Source:
MTU Friedrichshafen
GmbH
Introduction Centrifugal
CompressorTurbocharger
Introduction
6Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Source:
MTU Friedrichshafen GmbH
Performance Map
Introduction
Centrifugal
Compressor
isolines
efficiency
Turbocharger
Introduction
7Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Source:
MTU Friedrichshafen GmbH
Performance Map
Introduction
Centrifugal
Compressor
isolines
efficiency
Turbocharger
1. Objective: Increase Efficiency
Introduction
8Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
full-load curve
Source:
MTU Friedrichshafen GmbH
Performance Map
Introduction
Centrifugal
Compressor
isolines
efficiency
Turbocharger
1. Objective: Increase Efficiency
Introduction
9Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
full-load curve
Source:
MTU Friedrichshafen GmbH
Performance Map
Introduction
Centrifugal
Compressor
isolines
efficiency
Turbocharger
1. Objective: Increase Efficiency
Introduction
10Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
full-load curve
Source:
MTU Friedrichshafen GmbH
Performance Map
Introduction
Centrifugal
Compressor
isolines
efficiency
Turbocharger
1. Objective: Increase Efficiency
2. Objective: Increase Performance Map Width
Introduction
11Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
1. Objective: Increase Efficiency
2. Objective: Increase Performance Map Width
Problem: A pure aerodynamic optimization often leads
to a poor structural integrity.
1. Constraint: Von Mises Stresses
2. Constraint: Eigenfrequency
CFD
CSM
Contents
12Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
Optimization-Workflow
Results
Workflow
13Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Workflow - Parametrization
14Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Impeller
Diffuser
Volute
Workflow - Parametrization
15Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
3D Camber Surfacewith variable
blade ruling
Meridional Betaangle - Distribution
Source:
Friendship Systems
Workflow - Parametrization
16Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Thicknessdistribution
3D Blade
Source:
Friendship Systems
Workflow - Parametrization
17Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Geometry Export:
CFD (Meridional Contour, Blades) → geomTurbo (Numeca)
CSM (Impeller Solid) → Parasolid
Solid Final 3D Impeller and Diffuser
Source:
Friendship Systems
Workflow - Parametrization
18Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
A
AA-A
Volute
Geometry Export:
CFD → Parasolid
Source:
Friendship Systems
Workflow - Parametrization
19Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Parametrisierung
• Hub / Shroud
• Blades
• Main- and splitterblade
With variable blade ruling and non-linear
Leading Edge
• Diffuser
With variable blade ruling and non-linear
Leading/Trailing Edge
• Impeller back
• Volute
Workflow
20Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Workflow - CFD
21Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Solver Numeca FINE/Turbo
Objectives:
• Isentropic Efficiency
𝜂𝐷𝑃
• Performance Map Width𝜋ℎ𝑖𝑔ℎ𝑙𝑦 𝑡ℎ𝑟𝑜𝑡𝑡𝑙𝑒𝑑
𝜋𝐷𝑃
Constraints:
• Total Pressure Ratio
𝜋𝐷𝑃
• Choke Mass Flow
Workflow - CSM
22Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Von Mises Stress
Main blade
Fillet
Constraints:
• 1. blade eigenfrequency
• Max. von Mises stress:
• Main blade
• Splitter blade
• Fillet
• Bottom
• Drill
low
high Splitter
BottomCalculix
Drill
Workflow
23Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Workflow
Contents
24Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Introduction
Optimization-Workflow
Results
Results
25Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Results
• Evolutionary Algorithm + RSM
• 59 Parameters
• 1313 Designs
Results
26Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Results
Choke-Mass flow > Choke_constraint
PI > PI_constraint
baseline
selected DesignsD477
D1808
Results
27Gas Turbines and Aerospace Propulsion | Johannes Ratz 26.09.2019
Results
𝜂𝐷𝑃 → + 2.2 percentage points
𝜋𝐷𝑃 → - 0.1 (3.25%)
Map width (ሶ𝑚𝐶ℎ𝑜𝑘𝑒− ሶ𝑚𝑆𝑡𝑎𝑙𝑙
ሶ𝑚𝐶ℎ𝑜𝑘𝑒)
→ + 5.3 percentage points
D477
𝜂𝐷𝑃 → + 1.4 percentage points
𝜋𝐷𝑃 → - 0.17 (5.5%)
Map width (ሶ𝑚𝐶ℎ𝑜𝑘𝑒− ሶ𝑚𝑆𝑡𝑎𝑙𝑙
ሶ𝑚𝐶ℎ𝑜𝑘𝑒)
→ + 5 percentage points
D1808
Compliance of
structural constraints
The authors acknowledge the financial support
by the Federal Ministry for Economic Affairs and
Energy of Germany (BMWi) in the project
GAMMA (project number 03ET1469).
Thank You for Your Attention!