A Hybrid Inverse Design Method for Axisymmetric Bodies in Incompressible Flow

The upgraded elastic surface algorithm (UESA) is a physical inverse design method that was recently developed for a compressor cascade with double-circular-arc blades. In this method, the blade walls are modeled as elastic Timoshenko beams that smoothly deform because of the difference between the target and current pressure distributions. Nevertheless, the UESA is completely unstable for a compressor cascade with an intense normal shock, which causes a divergence due to the high pressure difference near the shock and the displacement of shock during the geometry corrections. In this study, the UESA was stabilized for the inverse design of a compressor cascade with normal shock, with no geometrical filtration. In the new version of this method, a distribution for the elastic modulus along the Timoshenko beam was chosen to increase its stiffness near the normal shock and to control the high deformations and oscillations in this region. Furthermore, to prevent surface oscillations, nodes need to be constrained to move perpendicularly to the chord line. With these modifications, the instability and oscillation were removed through the shape modification process. Two design cases were examined to evaluate the method for a transonic cascade with normal shock. The method was also capable of finding a physical pressure distribution that was nearest to the target one.

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Inverse Design of Axial-Flow Compressor Blades Using Elastic Surface Algorithm in Subsonic and Transonic Flow Regimes With Separation

Volume 2C: Turbomachinery ◽

10.1115/gt2016-56717 ◽

2016 ◽

Author(s):

M. H. Noorsalehi ◽

M. Nili-Ahamadabadi ◽

E. Shirani ◽

M. Safari

Keyword(s):

Pressure Distribution ◽

Transonic Flow ◽

Design Method ◽

Axial Flow ◽

Flow Regimes ◽

Inverse Design ◽

Elastic Surface ◽

Axial Flow Compressor ◽

Inverse Design Method ◽

Flow Compressor

In this study, a new inverse design method called Elastic Surface Algorithm (ESA) is developed and enhanced for axial-flow compressor blade design in subsonic and transonic flow regimes with separation. ESA is a physically based iterative inverse design method that uses a 2D flow analysis code to estimate the pressure distribution on the solid structure, i.e. airfoil, and a 2D solid beam finite element code to calculate the deflections due to the difference between the calculated and target pressure distributions. In order to enhance the ESA, the wall shear stress distribution, besides pressure distribution, is applied to deflect the shape of the airfoil. The enhanced method is validated through the inverse design of the rotor blade of the first stage of an axial-flow compressor in transonic viscous flow regime. In addition, some design examples are presented to prove the effectiveness and robustness of the method. The results of this study show that the enhanced Elastic Surface Algorithm is an effective inverse design method in flow regimes with separation and normal shock.

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An inverse design method of the acoustic lens

Applied Physics Letters ◽

10.1063/5.0059713 ◽

2021 ◽

Vol 119 (15) ◽

pp. 153503

Author(s):

Chengfu Gu ◽

Zengtao Yang ◽

Hua Wang

Keyword(s):

Design Method ◽

Inverse Design ◽

Acoustic Lens ◽

Inverse Design Method

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Hydrodynamic Design System for Pumps Based on 3-D CAD, CFD, and Inverse Design Method

Journal of Fluids Engineering ◽

10.1115/1.1471362 ◽

2002 ◽

Vol 124 (2) ◽

pp. 329-335 ◽

Cited By ~ 62

Author(s):

Akira Goto ◽

Motohiko Nohmi ◽

Takaki Sakurai ◽

Yoshiyasu Sogawa

Keyword(s):

Computer Aided Design ◽

High Performance ◽

Design Method ◽

High Reliability ◽

Secondary Flows ◽

System Structure ◽

Inverse Design ◽

Design System ◽

Centrifugal Impeller ◽

Inverse Design Method

A computer-aided design system has been developed for hydraulic parts of pumps including impellers, bowl diffusers, volutes, and vaned return channels. The key technologies include three-dimensional (3-D) CAD modeling, automatic grid generation, CFD analysis, and a 3-D inverse design method. The design system is directly connected to a rapid prototyping production system and a flexible manufacturing system composed of a group of DNC machines. The use of this novel design system leads to a drastic reduction of the development time of pumps having high performance, high reliability, and innovative design concepts. The system structure and the design process of “Blade Design System” and “Channel Design System” are presented. Then the design examples are presented briefly based on the previous publications, which included a centrifugal impeller with suppressed secondary flows, a bowl diffuser with suppressed corner separation, a vaned return channel of a multistage pump, and a volute casing. The results of experimental validation, including flow fields measurements, were also presented and discussed briefly.

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Multi-Objective Optimization of a High Specific Speed Centrifugal Volute Pump Using 3D Inverse Design Coupled With CFD Simulations

Volume 3B: Fluid Applications and Systems ◽

10.1115/ajkfluids2019-4676 ◽

2019 ◽

Author(s):

Luying Zhang ◽

Gabriel Davila ◽

Mehrdad Zangeneh

Keyword(s):

Surrogate Model ◽

Design Method ◽

Inverse Design ◽

Multi Objective Optimization ◽

Blade Angle ◽

Multi Objective ◽

Specific Speed ◽

Meridional Shape ◽

Inverse Design Method ◽

Conventional Optimization

Abstract This paper presents three different multi-objective optimization strategies for a high specific speed centrifugal volute pump design. The objectives of the optimization consist of maximizing the efficiency and minimizing the cavitation while maintaining the Euler head. The first two optimization strategies use a 3D inverse design method to parametrize the blade geometry. Both meridional shape and 3D blade geometry is changed during the optimization. In the first approach Design of Experiment method is used and the efficiency computed from CFD computations, while cavitation is evaluated by using minimum pressure on blade surface predicted by 3D inverse design method. The design matrix is then used to create a surrogate model where optimization is run to find the best tradeoff between cavitation and efficiency. This optimized geometry is manufactured and tested and is found to be 3.9% more efficient than the baseline with little cavitation at high flow. In the second approach the 3D inverse design method output is used to compute the efficiency and cavitation parameters and this leads to considerable reduction to the computational time. The resulting optimized geometry is found to be similar to the more computationally expensive solution based on 3D CFD results. In order to compare the inverse design based optimization to the conventional optimization an equivalent optimization is carried out by parametrizing the blade angle and meridional shape. Two different approaches are used for conventional optimization one in which the blade angle at TE is not constrained and one in which blade angles are constrained. In both cases larger variation in head is obtained when compared with the inverse design approach. This makes it impossible to create an accurate surrogate model. Furthermore, the efficiency levels in the conventional optimization is generally lower than the inverse design based optimization.

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