Efficient Design Optimization by Physics-Based Direct Manipulation Free-Form Deformation

An aerodynamic design optimization of a hypersonic rocket sled deflector is presented using the free-form deformation (FFD) technique. The objective is to optimize the aerodynamic shape of the hypersonic rocket sled deflector to increase its negative lift and enhance the motion stability of the rocket sled. The FFD technique is selected as the aerodynamic shape parameterization method, and the continuous adjoint method based on the gradient method is used to search the optimization in the geometric shape parameter space; the computational fluid dynamics method for a hypersonic rocket sled is employed. An automatic design optimization method for the deflector is carried out based on the aerodynamic requirements of the rocket sled. The optimization results show that the optimized deflector meets the design requirement of increasing the negative lift under the constraint of drag. By improving the pressure distribution on the surface of the deflector, the negative lift is increased by 7.39%, which confirms the effectiveness of the proposed method.

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Direct manipulation of free-form deformation using curve-pairs

Computer-Aided Design ◽

10.1016/j.cad.2012.09.004 ◽

2013 ◽

Vol 45 (3) ◽

pp. 605-614 ◽

Cited By ~ 12

Author(s):

Gang Xu ◽

Kin-chuen Hui ◽

Wen-bing Ge ◽

Guo-zhao Wang

Keyword(s):

Free Form ◽

Direct Manipulation ◽

Free Form Deformation

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Aerodynamic Design Optimization of an Axial Flow Compressor Stator Using Parameterized Free-Form Deformation

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4044692 ◽

2019 ◽

Vol 141 (10) ◽

Cited By ~ 1

Author(s):

Richard Amankwa Adjei ◽

WeiZhe Wang ◽

YingZheng Liu

Keyword(s):

Genetic Algorithm ◽

Flow Field ◽

Design Optimization ◽

Operating Conditions ◽

Free Form ◽

Aerodynamic Design ◽

Objective Functions ◽

Aerodynamic Design Optimization ◽

Design Variables ◽

Free Form Deformation

AbstractThis paper describes an aerodynamic design optimization of a highly loaded compressor stator blade using parameterized free-form deformation (FFD). The optimization methodology presented utilizes a B-spline-based FFD control volume to map the blade from the object space to the parametric space via transformation operations in order to perturb the blade surface. Coupled with a multi-objective genetic algorithm (MOGA) and a Gaussian process-based response surface method (RSM), a fully automated iterative loop was used to run the optimization on a fitted correlation function. A weighted average reduction of 6.1% and 36.9% in total pressure loss and exit whirl angle was achieved, showing a better compromise of objective functions with smoother blade shape than other results obtained in the open literature. Data mining of the Pareto set of optimums revealed four groups of data interactions of which some design variables were found to have skewed scatter relationship with objective functions and can be redefined for further improvement of performance. Analysis of the flow field showed that the thinning of the blade at midspan and reduction in camber distribution were responsible for the elimination of the focal-type separation vortex by redirecting the secondary flow in an axially forward direction toward the midspan and near the hub endwall downstream. Furthermore, the reduction in exit whirl angle especially at the shroud was due to the mild bow shape which generated radial forces on the flow field thereby reducing the flow diffusion rate at the suction surface corner. This effect substantially delayed or eliminated the formation of corner separation at design and off-design operating conditions. Parameterized FFD was found to have superior benefits of smooth surface generation with low number of design variables while maintaining a good compromise between objective functions when coupled with a genetic algorithm.

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Direct manipulation of RDMS free form deformation

2009 11th IEEE International Conference on Computer-Aided Design and Computer Graphics ◽

10.1109/cadcg.2009.5246931 ◽

2009 ◽

Author(s):

Gang Xu ◽

Kin-Chuen Hui ◽

Xiao-Diao Chen ◽

Guo-Zhao Wang

Keyword(s):

Free Form ◽

Direct Manipulation ◽

Free Form Deformation

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Multidisciplinary Design Optimization for Performance Improvement of an Axial Flow Fan Using Free-Form Deformation

Journal of Turbomachinery ◽

10.1115/1.4048793 ◽

2020 ◽

Vol 143 (1) ◽

Author(s):

Richard Amankwa Adjei ◽

Chengwei Fan ◽

WeiZhe Wang ◽

YingZheng Liu

Keyword(s):

Data Mining ◽

Design Optimization ◽

Performance Improvement ◽

Multidisciplinary Design Optimization ◽

Static Stress ◽

Chord Length ◽

Multidisciplinary Design ◽

Free Form ◽

Free Form Deformation ◽

Operating Points

Abstract This paper describes a multidisciplinary design optimization for performance improvement of an electric-ducted fan rotor using free-form deformation (FFD) and data mining techniques. A practical partitioning approach for FFD parameterization was applied in combination with engineering design parameters to optimize the fan rotor. Regression analysis was used to initially determine an approximation function for the blade static stress and subsequently integrated into a fully coupled iterative loop to optimize the blade considering two operating points. Two optimization solutions for 10 and 12 blades were performed. Percentage improvements in the efficiency of 1.05% and 1.32% were realized for 10 and 12 blades, respectively, at near peak efficiency flowrate. Also, blade static stress was reduced by percentages of 5.49% and 12.37% for 10 and 12 blades compared with the baseline. Data mining results revealed key design variable sensitivities where blade twist, sweep, chord, and hub thickness distribution were found to be the most influential for 12 blades while for 10 blades, blade lean, sweep and chord at the midspan and tip. The optimized blades were found to have a significant increase in chord from midspan to tip mimicking a wide chord fan blade particularly for 10 blades. Analysis of the flow field revealed that the axial velocity from 0.4 to 0.8 spanwise length increased significantly for the optimum blades due to the increase in blade twist and chord length at all stable operating points. However, the leakage trajectory relative to the blade chord was observed to be larger and interacted with the trailing edge wake flow downstream for the optimum blades at near-stall conditions. Furthermore, the increase in chord length and the thinning of the blade close to the trailing edge from 0.4 to 0.8 span reduced the suction-side blade loading and static stress.

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