Design Example of Three Dimensional Viscous Inverse Design Software TURBOdesign-2 : Design of the Blade Geometry of Swept Transonic Fan Rotors

Abstract This paper presents three different multiobjective 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 three-dimensional (3D) inverse design method to parametrize the blade geometry. Both meridional shape and 3D blade geometry are changed during the optimization. In the first approach, design of experiment (DOE) method is used and the pump efficiency is obtained from computational fluid dynamics (CFD) simulations, 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 reduced cavitation at high flow. In the second approach, only 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 computationally more 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.

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Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

Journal of Turbomachinery ◽

10.1115/1.2841219 ◽

1999 ◽

Vol 121 (1) ◽

pp. 119-126 ◽

Cited By ~ 8

Author(s):

E. Casartelli ◽

A. P. Saxer ◽

G. Gyarmathy

Keyword(s):

Static Pressure ◽

Flow Analysis ◽

Three Dimensional ◽

Pressure Rise ◽

Leading Edge ◽

Inverse Design ◽

Navier Stokes ◽

Two Dimensional ◽

Characteristic Lines ◽

Design Software

The flow field in a subsonic vaned radial diffuser of a single-stage centrifugal compressor is numerically investigated using a three-dimensional Navier–Stokes solver (TASCflow) and a two-dimensional analysis and inverse-design software package (MISES). The vane geometry is modified in the leading edge area (two-dimensional blade shaping) using MISES, without changing the diffuser throughflow characteristics. An analysis of the two-dimensional and three-dimensional effects of two redesigns on the flow in each of the diffuser subcomponents is performed in terms of static pressure recovery, total pressure loss production, and secondary flow reduction. The computed characteristic lines are compared with measurements, which confirm the improvement obtained by the leading edge redesign in terms of increased pressure rise and operating range.

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Design of the Blade Geometry of Swept Transonic Fans by 3D Inverse Design

Volume 6: Turbo Expo 2003, Parts A and B ◽

10.1115/gt2003-38770 ◽

2003 ◽

Cited By ~ 7

Author(s):

H. Watanabe ◽

M. Zangeneh

Keyword(s):

Inverse Method ◽

Design Method ◽

Pressure Ratio ◽

Inverse Design ◽

Specific Work ◽

Design Practice ◽

Blade Loading ◽

Inverse Design Method ◽

Transonic Fan ◽

Blade Geometry

The application of sweep in the design of transonic fans has been shown to be an effective method of controlling the strength and position of the shock wave at the tip of transonic fan rotors, and the control of corner separations in stators. In rotors sweep can extend the range significantly. However, using sweep in conventional design practice can also result in a change in specific work and therefore pressure ratio. As a result, laborious iterations are required in order to recover the correct specific work and pressure ratio. In this paper, the blade geometry of a transonic fan is designed with sweep using a 3D inverse design method in which the blade geometry is computed for a specified distribution of blade loading. By comparing the resulting flow field in the conventionally and inversely designed swept rotors, it is shown that it is possible to apply sweep without the need to iterate to maintain pressure ratio and specific work when using the inverse method.

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Development of Turbine Blade Profiles Using Iterative Inverse Design Methodology

Volume 1: Compressors, Fans and Pumps; Turbines; Heat Transfer; Combustion, Fuels and Emissions ◽

10.1115/gtindia2017-4553 ◽

2017 ◽

Author(s):

Nanthini Rajendran ◽

Bhamidi Prasad ◽

Y. V. S. S. Sanyasiraju

Keyword(s):

Pressure Distribution ◽

Design Methodology ◽

Turbine Blades ◽

Three Dimensional ◽

Geometric Constraints ◽

Inverse Design ◽

Normal Velocity ◽

Permeable Membrane ◽

Flow Parameters ◽

Blade Geometry

An iterative inverse design methodology is used to design gas turbine blades for the prescribed flow conditions. The input flow parameter considered here is the pressure distribution along the suction and pressure surfaces of the blade. The flow is regarded as inviscid. A guess blade is presumed and the flow analysis over the blade is determined using the existing commercial software. In case of mismatch of the flow parameters, the guessed profile surface is considered as a permeable membrane and the normal velocity on the blade surface is computed by conservation of momentum flux approach. The computed normal velocity is used to revise the blade geometry by mass conservation principle till the flow parameters converge. A few geometric constraints are enforced on the model to avoid quixotic blade model. The validation of the above method is being done using NACA profiles. The robustness of the method is verified by using various combinations of NACA blade profiles, where different initial guessed profiles are taken for the same prescribed pressure distribution. This approach can be extended to three dimensional cases. To incorporate the complications attached with the three dimensional flows, three two dimensional sections can be considered on the blade geometry namely at hub, mid span and tip.

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A Design Study of Radial Inflow Turbines With Splitter Blades in Three-Dimensional Flow

Journal of Turbomachinery ◽

10.1115/1.2836650 ◽

1996 ◽

Vol 118 (2) ◽

pp. 353-361 ◽

Cited By ~ 3

Author(s):

W. D. Tjokroaminata ◽

C. S. Tan ◽

W. R. Hawthorne

Keyword(s):

Reverse Flow ◽

Three Dimensional ◽

Flow Region ◽

Inverse Design ◽

Design Technique ◽

Design Study ◽

Three Dimensional Flow ◽

Dimensional Flow ◽

Rotational Part ◽

Blade Geometry

An inverse design technique to design turbomachinery blading with splitter blades in three-dimensional flow is developed. It is based on the use of Clebsch transformation, which allows the velocity field to be written as a potential part and a rotational part. It is shown that the rotational part can be expressed in terms of the mean swirl schedule (the circumferential average of the product of radius and tangential velocity) and the blade geometry that includes the main blade as well as the splitter blade. This results in an inverse design approach, in which both the main and the splitter blade geometry are determined from a specification of the swirl schedule. Previous design study of a heavily loaded radial inflow turbine, without splitter blades, for a rather wide variety of specified mean swirl schedules results in a blade shape with unacceptable nonradial blade filament; the resulting reduced static pressure distribution yields an “inviscid reverse flow region” covering almost the first half of the blade pressure surface. When the inverse design technique is applied to the design study of the turbine wheel with splitter blades, the results indicate that the use of splitter blades is an effective means for making the blade filament at an axial location more radial as well as a potential means for eliminating any “inviscid reverse flow” region that may exist on the pressure side of the blades.

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A Design Study of Radial Inflow Turbines With Splitter Blades in Three-Dimensional Flow

Volume 1: Turbomachinery ◽

10.1115/94-gt-036 ◽

1994 ◽

Cited By ~ 2

Author(s):

W. D. Tjokroamlnata ◽

C. S. Tan ◽

W. R. Hawthorne

Keyword(s):

Reverse Flow ◽

Three Dimensional ◽

Flow Region ◽

Inverse Design ◽

Design Technique ◽

Design Study ◽

Three Dimensional Flow ◽

Dimensional Flow ◽

Rotational Part ◽

Blade Geometry

An inverse design technique to design turbomachinery blading with splitter blades in three-dimensional flow is developed. It is based on the use of Clebsch transformation which allows the velocity field to be written as a potential part and a rotational part. It is shown that the rotational part can be expressed in terms of the mean swirl schedule (the circumferential average of the product of radius and tangential velocity) and the blade geometry that includes the main blade as well as the splitter blade. This results in an inverse design approach in which both the main and the splitter blade geometry are determined from a specification of the swirl schedule. Previous design study of a heavily-loaded radial inflow turbine, without splitter blades, for a rather wide variety of specified mean swirl schedules result in a blade shape with unacceptable non-radial blade filament; the resulting reduced static pressure distribution yields an “inviscid reverse flow region”1 covering almost the first half of the blade pressure surface. When the inverse design technique is applied to the design study of the turbine wheel with splitter blades, the results indicate that the use of splitter blades is an effective means for making the blade filament at an axial location more radial as well as a potential means for eliminating any “inviscid reverse flow” region that may exist on the pressure side of the blades.

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Implementation of Three-Dimensional Inverse Design and Its Application to Improve the Compressor Performance

Energies ◽

10.3390/en13205378 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5378

Author(s):

Yu Duan ◽

Qun Zheng ◽

Bin Jiang ◽

Aqiang Lin ◽

Wenfeng Zhao

Keyword(s):

Fluid Dynamic ◽

Thickness Distribution ◽

Three Dimensional ◽

Axial Compressor ◽

Design Tool ◽

Inverse Design ◽

Design System ◽

Pressure Loading ◽

Design Algorithm ◽

Transonic Fan

The implementation of a three-dimensional viscous inverse design used for an axial compressor is introduced in this paper. The derivation process of the inverse design algorithm is also described in detail. Moreover, an improved blade update method and a modified relaxation factor are included to enhance the inverse design algorithm. The inverse design is built on an in-house inverse design module coupled with commercial Computational Fluid Dynamic (CFD) software NUMECATM. In contrast to analysis design, the pressure loading and the normal thickness distribution along the blade surfaces are prescribed during the process of inverse design. The numerical methods used to solve the flow field are verified using the experimental data of the transonic fan rotor NASA Rotor 67. A recovery test for the Rotor 67 is carried out to validate the developed three-dimensional inverse design tool. To explore the potential application of the inverse design system, it is then used to improve the aerodynamic performance of a transonic fan Rotor 67 and a multi-row compressor Stage 35 at a near peak efficiency point by reorganizing the pressure loading distribution on the blade surfaces.

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Investigation of an Inversely Designed Centrifugal Compressor Stage—Part I: Design and Numerical Verification

Journal of Turbomachinery ◽

10.1115/1.1645868 ◽

2004 ◽

Vol 126 (1) ◽

pp. 73-81 ◽

Cited By ~ 21

Author(s):

M. Zangeneh ◽

M. Schleer ◽

F. Pløger ◽

S. S. Hong ◽

C. Roduner ◽

...

Keyword(s):

Centrifugal Compressor ◽

Design Method ◽

Three Dimensional ◽

Leading Edge ◽

Inverse Design ◽

Numerical Verification ◽

Appreciable Effect ◽

Tip Leakage Flow ◽

Flow Angle ◽

Blade Geometry

In this paper the three-dimensional inverse design code TURBOdesign-1 is applied to the design of the blade geometry of a centrifugal compressor impeller with splitter blades. In the design of conventional impellers the splitter blades normally have the same geometry as the full blades and are placed at mid-pitch location between the two full blades, which can usually result in a mismatch between the flow angle and blade angles at the splitter leading edge. In the inverse design method the splitter and full blade geometry is computed independently for a specified distribution of blade loading on the splitter and full blades. In this paper the basic design methodology is outlined and then the flow in the conventional and inverse designed impeller is compared in detail by using computational fluid dynamics (CFD) code TASCflow. The CFD results confirm that the inverse design impeller has a more uniform exit flow, better control of tip leakage flow and higher efficiency than the conventional impeller. The results also show that the shape of the trailing edge geometry has a very appreciable effect on the impeller Euler head and this must be accurately modeled in all CFD computations to ensure closer match between CFD and experimental results. Detailed measurements are presented in part II of the paper.

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Unsteady Three-Dimensional Analysis of Inlet Distortion in a Transonic Fan

Fluids Engineering ◽

10.1115/imece2006-13145 ◽

2006 ◽

Author(s):

Peng Sun ◽

Guotal Feng

Keyword(s):

Shock Wave ◽

Total Pressure ◽

Large Scale ◽

Three Dimensional ◽

Navier Stokes ◽

Inlet Distortion ◽

Flow Loss ◽

Large Scale Vortex ◽

Total Temperature ◽

Transonic Fan

A time-accurate three-dimensional Navier-Stokes solver of the unsteady flow field in a transonic fan was carried out using "Fluent-parallel" in a parallel supercomputer. The numerical simulation focused on a transonic fan with inlet square wave total pressure distortion and the analysis of result consisted of three aspects. The first was about inlet parameters redistribution and outlet total temperature distortion induced by inlet total pressure distortion. The pattern and causation of flow loss caused by pressure distortion in rotor were analyzed secondly. It was found that the influence of distortion was different at different radial positions. In hub area, transportation-loss and mixing-loss were the main loss patterns. Distortion not only complicated them but enhanced them. Especially in stator, inlet total pressure distortion induced large-scale vortex, which produced backflow and increased the loss. While in casing area, distortion changed the format of shock wave and increased the shock loss. Finally, the format of shock wave and the hysteresis of rotor to distortion were analyzed in detail.

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Inverse Design of 3D Multi-Stage Transonic Fans at Dual Operating Points

Volume 6B: Turbomachinery ◽

10.1115/gt2013-95062 ◽

2013 ◽

Cited By ~ 2

Author(s):

James H. Page ◽

Paul Hield ◽

Paul G. Tucker

Keyword(s):

Design Method ◽

Pressure Ratio ◽

Three Dimensional ◽

Inverse Design ◽

Flow Angle ◽

Trade Offs ◽

Multi Stage ◽

Full Speed ◽

Computational Fluid Dynamics Cfd ◽

Operating Points

Semi-inverse design is the automatic re-cambering of an aerofoil, during a computational fluid dynamics (CFD) calculation, in order to achieve a target lift distribution while maintaining thickness, hence “semi-inverse”. In this design method, the streamwise distribution of curvature is replaced by a stream-wise distribution of lift. The authors have developed an inverse design code based on the method of Hield (2008) which can rapidly design three-dimensional fan blades in a multi-stage environment. The algorithm uses an inner loop to design to radially varying target lift distributions, an outer loop to achieve radial distributions of stage pressure ratio and exit flow angle, and a choked nozzle to set design mass flow. The code is easily wrapped around any CFD solver. In this paper, we describe a novel algorithm for designing simultaneously for specified performance at full speed and peak efficiency at part speed, without trade-offs between the targets at each of the two operating points. We also introduce a novel adaptive target lift distribution which automatically develops discontinuous changes of calculated magnitude, based on the passage shock, eliminating erroneous lift demands in the shock vicinity and maintaining a smooth aerofoil.

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