Improving Aerodynamic Matching of Axial Compressor Blading Using a Three-Dimensional Multistage Inverse Design Method

2005 ◽  
Vol 129 (1) ◽  
pp. 108-118 ◽  
Author(s):  
M. P. C. van Rooij ◽  
T. Q. Dang ◽  
L. M. Larosiliere
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Three Dimensional ◽  
Computational Time ◽  
Design Calculation ◽  
Pressure Loading ◽  
Design Intent ◽  
Design Point ◽  
Analysis And Design ◽  
Blade Row

Current turbomachinery design systems increasingly rely on multistage CFD as a means to diagnose designs and assess performance potential. However, design weaknesses attributed to improper stage matching are addressed using often ineffective strategies involving a costly iterative loop between blading modification, revision of design intent, and further evaluation of aerodynamic performance. A scheme is proposed herein which greatly simplifies the design point blade row matching process. It is based on a three-dimensional viscous inverse method that has been extended to allow blading analysis and design in a multi-blade row environment. For computational expediency, blade row coupling is achieved through an averaging-plane approximation. To limit computational time, the inverse method was parallelized. The proposed method allows improvement of design point blade row matching by direct regulation of the circulation capacity of the blading within a multistage environment. During the design calculation, blade shapes are adjusted to account for inflow and outflow conditions while producing a prescribed pressure loading. Thus, it is computationally ensured that the intended pressure-loading distribution is consistent with the derived blading geometry operating in a multiblade row environment that accounts for certain blade row interactions. The viability of the method is demonstrated in design exercises involving the rotors of a 2.5 stage, highly loaded compressor. Individually redesigned rotors display mismatching when run in the 2.5 stage, evident as a deviation from design intent. However, simultaneous redesign of the rotors in their multistage environment produces the design intent, indicating that aerodynamic matching has been achieved.

Improving Aerodynamic Matching of Axial Compressor Blading Using a 3D Multistage Inverse Design Method

2005 ◽  
Author(s):  
M. P. C. van Rooij ◽  
T. Q. Dang ◽  
L. M. Larosiliere
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Design Calculation ◽  
Pressure Loading ◽  
Design Point ◽  
Analysis And Design ◽  
Blade Row ◽  
Inverse Design Method ◽  
Stage Matching

Current turbomachinery design systems increasingly rely on multistage CFD as a means to diagnose designs and assess performance potential. However, design weaknesses attributed to improper stage matching are addressed using often ineffective strategies involving a costly iterative loop between blading modification, revision of design intent, and further evaluation of aerodynamic performance. A scheme is proposed herein which greatly simplifies the design point blade row matching process. It is based on a three-dimensional viscous inverse method that has been extended to allow blading analysis and design in a multi-blade row environment. For computational expediency, blade row coupling is achieved through an averaging-plane approximation. The proposed method allows improvement of design point blade row matching by direct regulation of the circulation capacity of the blading within a multistage environment. During the design calculation, blade shapes are adjusted to account for inflow and outflow conditions while producing a prescribed pressure loading. Thus, it is computationally ensured that the intended pressure-loading distribution is consistent with the derived blading geometry operating in a multi-blade row environment that accounts for certain blade row interactions. The viability of the method is explored in design exercises on a 2.5-stage, highly loaded compressor.

A Three-Dimensional Inverse Method for Turbomachinery: Part I—Theory

1990 ◽  
Vol 112 (3) ◽  
pp. 346-354 ◽  
Author(s):  
J. E. Borges
Keyword(s):  
Velocity Field ◽  
Inverse Method ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Inverse Methods ◽  
Meridional Section ◽  
Low Speed ◽  
Present Procedure ◽  
Blade Row ◽  
The Mean

There are surprisingly few inverse methods described in the literature that are truly three dimensional. Here, one such method is presented. This technique uses as input a prescribed distribution of the mean swirl, i.e., radius times mean tangential velocity, given throughout the meridional section of the machine. In the present implementation the flow is considered inviscid and incompressible and is assumed irrotational at the inlet to the blade row. In order to evaluate the velocity field inside the turbomachine, the blades (supposed infinitely thin) are replaced by sheets of vorticity, whose strength is related to the specified mean swirl. Some advice on the choice of a suitable mean swirl distribution is given. In order to assess the usefulness of the present procedure, it was decided to apply it to the design of an impeller for a low-speed radial-inflow turbine. The results of the tests are described in the second part of this paper.

Three-Dimensional Paddle Shift Modeling for IC Packaging

2004 ◽  
Vol 127 (3) ◽  
pp. 324-334 ◽  
Author(s):  
Chien-Chang Pei ◽  
Sheng-Jye Hwang
Keyword(s):  
Structural Analysis ◽  
Integrated Circuits ◽  
Three Dimensional ◽  
Void Formation ◽  
Model Performance ◽  
Computational Time ◽  
Pressure Loading ◽  
Filling Process ◽  
Molding Process ◽  
Incomplete Filling

The plastic packaging process for integrated circuits is subject to several fabrication defects. For packages containing leadframes, three major defects may occur in the molding process alone, namely, incomplete filling and void formation, wire sweep, and paddle shift. Paddle shift is the deflection of the leadframe pad and die. Excessive paddle shift reduces the encapsulation protection for the components and may result in failures due to excessive wire sweep. Computer-aided analysis is one of the tools that could be used to simulate and predict the occurrence of such molding-process-induced defects, even prior to the commencement of mass production of a component. This paper presents a methodology for computational modeling and prediction of paddle shift during the molding process. The methodology is based on modeling the flow of the polymer melt around the leadframe and paddle during the filling process, and extracting the pressure loading induced by the flow on the paddle. The pressure loading at different times during the filling process is then supplied to a three-dimensional, static, structural analysis module to determine the corresponding paddle deflections at those times. The paper outlines the procedures used to define the relevant geometries and to generate the meshes in the “fluid” and “structural” subdomains, and to ensure the compatibility of these meshes for the transfer of pressure loadings. Results are shown for a full paddle shift simulation. The effect on the overall model performance of different element types for the mold-filling analysis and the structural analysis is also investigated and discussed. In order to obtain more accurate results and in a shorter computational time for the combined (fluid and structural) paddle shift analysis, it was found that higher-order elements, such as hexahedra or prisms, are more suitable than tetrahedra.

Multi-Objective Optimization of a High Specific Speed Centrifugal Volute Pump Using Three-Dimensional Inverse Design Coupled With Computational Fluid Dynamics Simulations

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Luying Zhang ◽  
Gabriel Davila ◽  
Mehrdad Zangeneh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Computational Time ◽  
Specific Speed ◽  
Meridional Shape ◽  
Inverse Design Method ◽  
Blade Geometry

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.

A Comparison Between the Design Point and Near-Stall Performance of an Axial Compressor

1990 ◽  
Vol 112 (1) ◽  
pp. 109-115 ◽  
Author(s):  
N. M. McDougall
Keyword(s):  
Rotor Blade ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Tip Clearance Flow ◽  
Design Point ◽  
Blade Row ◽  
Clearance Flow ◽  
Stator Blade

Detailed measurements have been made within an axial compressor operating both at design point and near stall. Rotor tip clearance was found to control the performance of the machine by influencing the flow within the rotor blade passages. This was not found to be the case in the stator blade row, where hub clearance was introduced beneath the blade tips. Although the passage flow was observed to be altered dramatically, no significant changes were apparent in the overall pressure rise or stall point. Small tip clearances in the rotor blade row resulted in the formation of corner separations at the hub, where the blade loading was highest. More representative clearances resulted in blockage at the tip due to the increased tip clearance flow. The effects that have been observed emphasize both the three-dimensional nature of the flow within compressor blade passages, and the importance of the flow in the endwall regions in determining the overall compressor performance.

scholarly journals Application of a three-dimensional viscous transonic inverse method to NASA rotor 67

2002 ◽  
Vol 216 (3) ◽  
pp. 243-255 ◽  
Author(s):  
W. T. Tiow ◽  
M Zangeneh
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Static Pressure ◽  
Three Dimensional ◽  
Test Case ◽  
Shock Formation ◽  
Pressure Loading ◽  
Design Computation ◽  
Computational Fluid Dynamics Cfd ◽  
Blade Geometry

The development and application of a three-dimensional inverse methodology in which the blade geometry is computed on the basis of the specification of static pressure loading distribution is presented. The methodology is based on the intensive use of computational fluid dynamics (CFD) to account for three-dimensional subsonic and transonic viscous flows. In the design computation, the necessary blade changes are determined directly by the discrepancies between the target and initial values, and the calculation converges to give the final blade geometry and the corresponding steady state flow solution. The application of the method is explored using a transonic test case, NASA rotor 67. Based on observations, it is conclusive that the shock formation and its intensity in such a high-speed turbomachinery flow are well defined on the loading distributions. Pressure loading is therefore as effective a design parameter as conventional inverse design quantities such as static pressure. Hence, from an understanding of the dynamics of the flow in the fan in relation to its pressure loading distributions, simple guidelines can be developed for the inverse method in order to weaken the shock formation. A qualitative improvement in performance is achieved in the redesigned fan. The final flowfield result is confirmed by a well-established commercial CFD package.

Design Method for Turbomachine Blades With Finite Thickness by the Circulation Method

1997 ◽  
Vol 119 (3) ◽  
pp. 539-543 ◽  
Author(s):  
J. Jiang ◽  
T. Dang
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Guide Vane ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Inlet Guide Vane ◽  
Impulse Turbine ◽  
Blade Thickness ◽  
Flow Limit ◽  
Design Calculations

This paper presents a procedure to extend a recently developed three-dimensional inverse method for infinitely thin blades to handle blades with finite thickness. In this inverse method, the prescribed quantities are the blade pressure loading and the blade thickness distributions, and the calculated quantity is the blade mean camber line. The method is formulated in the fully inverse mode whereby the blade shape is determined iteratively using the flow-tangency condition along the blade surfaces. Design calculations are presented for an inlet guide vane, an impulse turbine blade, and a compressor blade in the two-dimensional inviscid- and incompressible-flow limit. Consistency checks are carried out for these design calculations using a panel analysis method and the analytical solution for the Gostelow profile.

scholarly journals Design Method for Turbomachine Blades With Finite Thickness by the Circulation Method

1994 ◽  
Author(s):  
Jun Jiang ◽  
Thong Dang
Keyword(s):  
Inverse Method ◽  
Incompressible Flows ◽  
Design Method ◽  
Guide Vane ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Inlet Guide Vane ◽  
Impulse Turbine ◽  
Blade Thickness ◽  
Design Calculations

This paper presents a procedure to extend a well-developed fully three-dimensional inverse method for infinitely-thin blades to handle blades with finite thickness. In this inverse method, the prescribed quantities are the blade pressure loading and the blade thickness distributions, and the calculated quantity is the blade geometry. The method is formulated in the fully inverse mode whereby the blade shape is determined iteratively using the flow-tangency condition along the blade surfaces. This technique is demonstrated here in the first instance for the design of cascaded blades in inviscid and incompressible flows. Design calculations are presented for an inlet guide vane, an impulse turbine blade, and a compressor blade. Consistency checks are carried out for these design calculations using a panel analysis method and the analytical solution for the Gostelow profile.

A Three Dimensional Inverse Method in Turbomachinery: Part I — Theory

1989 ◽  
Author(s):  
João Eduardo Borges
Keyword(s):  
Velocity Field ◽  
Inverse Method ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Inverse Methods ◽  
Meridional Section ◽  
Low Speed ◽  
Present Procedure ◽  
Blade Row ◽  
The Mean

There are surprisingly few inverse methods described in the literature that are truly three-dimensional. Here, one such method is presented. This technique uses as input a prescribed distribution of the mean swirl, i.e., radius times mean tangential velocity, given throughout the meridional section of the machine. In the present implementation the flow is considered inviscid and incompressible and is assumed irrotational at inlet to the blade row. In order to evaluate the velocity field inside the turbomachine, the blades (supposed infinitely thin) are replaced by sheets of vorticity whose strength is related to the specified mean swirl. Some advice on the choice of a suitable mean swirl distribution is given. In order to assess the usefulness of the present procedure, it was decided to apply it to the design of an impeller of a low-speed radial-inflow turbine. The results of the tests are described in the second part of this paper.

Inverse or Design Calculations for Non-Potential Flow in Turbomachinery Blade Passages

1981 ◽  
Author(s):  
W. T. Thompkins ◽  
Siu Shing Tong
Keyword(s):  
Pressure Distribution ◽  
Potential Flow ◽  
Three Dimensional ◽  
Viscous Flows ◽  
Geometric Constraints ◽  
Design Calculation ◽  
Compressor Cascade ◽  
Surface Pressure Distribution ◽  
Blade Row ◽  
Design Calculations

A new inverse or design calculation procedure has been devised for non-potential flow fields and has been applied to turbomachinery blade row design. This technique uses as input quantities the surface pressure distribution and geometric constraints and may be used for two- or three-dimensional flows as well as inviscid or viscous flows. If a geometry satisfying both the constraints and the pressure distribution cannot be found, a solution satisfying the constraints and a relaxed pressure distribution is found. Calculational examples are presented for inviscid supersonic compressor cascade designs and the extension to three-dimensional flows discussed.

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