Optimum Design of Turbomachinery Components: A System Based Design

2000 ◽  
Author(s):  
Somanath Nagendra
Keyword(s):  
Shape Optimization ◽  
Design Optimization ◽  
Numerical Models ◽  
Turbine Blades ◽  
Optimization Procedure ◽  
Response Surfaces ◽  
Optimization Techniques ◽  
Geometric Constraints ◽  
Preliminary Design ◽  
Design Cycle

Abstract The advent of incredibly fast, increased memory computational systems enable a very systematic design integration of complex engineering modules using an integrated system based approach. Rapid turn-around time for investigating new design concepts is a primary force driving design productivity initiatives across industry. A system based integration focusing on tools for rapid design automation and preliminary design, (e.g. Closed Form Solutions, Response Surfaces, Approximate Numerical Models etc), finite element analysis coupled with optimization methods are needed. Numerical design algorithms (e.g. Sensitivity analysis methods, Feasible Direction methods, Genetic Algorithms, Simulated Annealing, Gradient based Algorithms etc.) at the preliminary and detailed design stages, would ensure higher quality designs from the beginning of the product design cycle. Resulting reliable, robust optimum designs from the preliminary design phase would enable to reduce the overall design cycle time. Large-scale engineering systems (like the gas turbine See Figure. 1) often involve many disciplines which are either loosely or tightly coupled to each other due to the multidisciplinary nature of the interactions. Designers have long recognized the need to decompose such systems into a set of smaller more tractable disciplines. This decomposition is usually based either on engineering disciplines or mathematical models governing the system. Narayan et al. [1] developed a multi-disciplinary design optimization procedure for the design of the aerodynamic shape of turbine blades for enhanced performance using shape optimization techniques. A multidisciplinary design optimization procedure for thin-walled high temperature components has been developed and demonstrated on different components Aerodynamic, heat transfer, structural and modal design objectives are integrated along with various constraint on the blade geometry for multidisciplinary shape optimization. The average blade temperature, maximum blade temperature and the blade weight are minimized with aerodynamic, structural, modal and geometric constraints. A methodology for performing mechanical design of turbine blade components is developed and tested.

scholarly journals Shape optimization of turbine blades with the integration of aerodynamics and heat transfer

1998 ◽  
Vol 4 (1) ◽  
pp. 21-42 ◽  
Author(s):  
J. N. Rajadas ◽  
A. Chattopadhyay ◽  
N. Pagaldipti ◽  
S. Zhang
Keyword(s):  
Heat Transfer ◽  
Shape Optimization ◽  
Tangential Force ◽  
Turbine Blades ◽  
Leading Edge ◽  
Optimization Techniques ◽  
Multidisciplinary Optimization ◽  
Heat Transfer Analysis ◽  
Maximum Temperature ◽  
Force Coefficient

A multidisciplinary optimization procedure, with the integration of aerodynamic and heat transfer criteria, has been developed for the design of gas turbine blades. Two different optimization formulations have been used. In the first formulation, the maximum temperature in the blade section is chosen as the objective function to be minimized. An upper bound constraint is imposed on the blade average temperature and a lower bound constraint is imposed on the blade tangential force coefficient. In the second formulation, the blade average and maximum temperatures are chosen as objective functions. In both formulations, bounds are imposed on the velocity gradients at several points along the surface of the airfoil to eliminate leading edge velocity spikes which deteriorate aerodynamic performance. Shape optimization is performed using the blade external and coolant path geometric parameters as design variables. Aerodynamic analysis is performed using a panel code. Heat transfer analysis is performed using the finite element method. A gradient based procedure in conjunction with an approximate analysis technique is used for optimization. The results obtained using both optimization techniques are compared with a reference geometry. Both techniques yield significant improvements with the multiobjective formulation resulting in slightly superior design.

An Energy Formulation for Parametric Size and Shape Optimization of Compliant Mechanisms

1999 ◽  
Vol 121 (2) ◽  
pp. 229-234 ◽  
Author(s):  
J. A. Hetrick ◽  
S. Kota
Keyword(s):  
Shape Optimization ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Optimization Procedure ◽  
Stress Constraints ◽  
Optimization Techniques ◽  
Mechanical Transmission ◽  
Dimensional Synthesis ◽  
Size And Shape ◽  
Mechanical Devices

Compliant mechanisms are jointless mechanical devices that take advantage of elastic deformation to achieve a force or motion transformation. An important step toward automated design of compliant mechanisms has been the development of topology optimization techniques. The next logical step is to incorporate size and shape optimization to perform dimensional synthesis of the mechanism while simultaneously considering practical design specifications such as kinematic and stress constraints. An improved objective formulation based on maximizing the energy throughput of a linear static compliant mechanism is developed considering specific force and displacement operational requirements. Parametric finite element beam models are used to perform the size and shape optimization. This technique allows stress constraints to limit the maximum stress in the mechanism. In addition, constraints which restrict the kinematics of the mechanism are successfully applied to the optimization problem. Resulting optimized mechanisms exhibit efficient mechanical transmission and meet kinematic and stress requirements. Several examples are given to demonstrate the effectiveness of the optimization procedure.

Numerical models for robust shape optimization of wind turbine blades

2016 ◽  
Vol 87 ◽  
pp. 849-862 ◽  
Author(s):  
Damir Vučina ◽  
Ivo Marinić-Kragić ◽  
Zoran Milas
Keyword(s):  
Shape Optimization ◽  
Wind Turbine ◽  
Numerical Models ◽  
Turbine Blades ◽  
Wind Turbine Blades

Aerodynamic preliminary design optimization of a centrifugal compressor turbocharger based on one-dimensional mean-line model

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lakhdar Bourabia ◽  
Cheikh Brahim Abed ◽  
Mahfoudh Cerdoun ◽  
Smail Khalfallah ◽  
Michaël Deligant ◽  
...  
Keyword(s):  
Design Optimization ◽  
Centrifugal Compressor ◽  
Optimization Design ◽  
Optimization Techniques ◽  
Solution Phase ◽  
Geometrical Parameters ◽  
Preliminary Design ◽  
Line Model ◽  
Content Type ◽  
One Dimensional

Purpose The purpose of this paper is the development of a new turbocharger compressor is a challenging task particularly when both wider operating range and higher efficiency are required. However, the cumbersome design effort and the inherent calculus burden can be significantly reduced by using appropriate design optimization approaches as an alternative to conventional design techniques. Design/methodology/approach This paper presents an optimization-based preliminary-design (OPD) approach based on a judicious coupling between evolutionary optimization techniques and a modified one-dimensional mean-line model. Two optimization strategies are considered. The first one is mono-objective and is solved using genetic algorithms. The second one is multi-objective and it is handled using the non-dominated sorting genetic algorithm-II. The proposed approach constitutes an automatic search process to select the geometrical parameters of the compressor, ensuring the most common requirements of the preliminary-design phase, with a minimum involvement of the designer. Findings The obtained numerical results demonstrate that the proposed tool can rapidly produce nearly optimal designs as an excellent basis for further refinement in the phase by using more complex analysis methods such as computational fluid dynamics and meta-modeling. Originality/value This paper outlines a new fast OBPD approach for centrifugal compressor turbochargers. The proposal adopts an inverse design method and consists of two main phases: a formulation phase and a solution phase. The complexity of the formulated problem is reduced by using a sensitivity analysis. The solution phase requires to link, in an automatic way, three processes, namely, optimization, design and analysis.

Size and Shape Optimization of Compliant Mechanisms: An Efficiency Formulation

1998 ◽  
Author(s):  
Joel A. Hetrick ◽  
Sridhar Kota
Keyword(s):  
Shape Optimization ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Optimization Procedure ◽  
Stress Constraints ◽  
Mechanical Efficiency ◽  
Optimization Techniques ◽  
Mechanical Transmission ◽  
Dimensional Synthesis ◽  
Size And Shape

Abstract Compliant mechanisms are jointless mechanical devices that take advantage of elastic deformation to achieve a force or motion transformation. A milestone toward systematic design of compliant mechanisms has been the development of topology optimization techniques. The next logical step is to incorporate size and shape optimization to identify the exact dimensional form of the mechanism. A new objective formulation based on maximizing the mechanical efficiency of a compliant mechanism is developed in order to perform the size and shape optimization. An advantage of this formulation is that precise control over the mechanism’s mechanical or geometric advantage can be enforced during optimization. Finite element beam models are used to perform dimensional synthesis of planar compliant mechanisms. This technique allows stress constraints to limit the maximum stress in the mechanism which improves the mechanism’s durability and flexibility. Resulting optimized mechanisms exhibit efficient mechanical transmission and meet kinematic and stress requirements. Several examples are given to demonstrate the effectiveness of the optimization procedure.

A Comparison of Equality Constraint Formulations for Concurrent Design Optimization

1996 ◽  
Author(s):  
Ravindra V. Tappeta ◽  
John E. Renaud
Keyword(s):  
Design Optimization ◽  
Optimization Procedure ◽  
Optimal Designs ◽  
Test Problems ◽  
Concurrent Design ◽  
Analysis And Design ◽  
Design Cycle ◽  
Simultaneous Analysis And Design ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

Abstract This paper investigates a concurrent approach for design optimization. The method of Simultaneous ANalysis and Design (SAND) is tested in application to three Multidisciplinary Design Optimization (MDO) test problems. A Generalized Reduced Gradient (GRG) optimizer and a Sequential Quadratic Programming (SQP) optimizer are compared with respect to their efficacy in handling three different forms of equality constraints referred to as compatibility constraints in the SAND based optimization procedure. Results highlight the need for both strategies in application of SAND based design to different engineering test problems. More importantly significant savings in the number of analyses required for design optimization are observed when using the SAND approach of concurrent design. SAND based design delivers on the promise of concurrent engineering, namely to develop optimal designs, working concurrently, while reducing design cycle time.

Shape Optimization of Multi-Element Airfoils Using Evolutionary Algorithms and Hybrid Unstructured Framework

2004 ◽  
Author(s):  
V. Ahuja ◽  
A. Hosangadi ◽  
Y. T. Lee
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Shape Optimization ◽  
Design Optimization ◽  
Optimization Procedure ◽  
Complex Design ◽  
Local Extrema ◽  
Present Design ◽  
Set Up ◽  
Comprehensive Framework

In this paper we present design optimization studies of multi-element airfoils utilizing evolutionary algorithms. The shape optimization process is carried out by utilization of high fidelity CFD based comprehensive framework. The framework comprises of a genetic algorithm based design optimization procedure coupled to the hybrid unstructured CRUNCH CFD® code and a grid generator. The genetic algorithm based optimization procedure is very robust, and searches the complex design landscape in an efficient and parallel manner. Furthermore, it can easily handle complexities in constraints and objectives and is disinclined to get trapped in local extrema regions. The fitness evaluations are carried out through a RANS based hybrid unstructured solver. The utilization of hybrid unstructured methodology provides flexibility in incorporating large changes in design and mesh regeneration is carried out in an automated manner through a scripting process within the grid generator GRIDGEN. The design optimization procedure is carried out simultaneously on both the stabilizer and the flap. Shape changes to the trailing edge of the flap strongly influence the secondary flow patterns that set up in the gap region between the stabilizer and the flap. These, in turn, are found to have a profound influence on lift and torque characteristics. The paper will discuss these results and provide details of the optimization procedure including coupling with hybrid unstructured framework and grid generator.

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