On the Coupling of Direct Design and Optimization Techniques for Mitigating the Turbomachinery Performance Test Risk

2013 ◽  
Author(s):  
Keiji Tajiri ◽  
Jinhui Zhao ◽  
William C. Hohlweg ◽  
Haijie Zhang
Keyword(s):  
New Product Development ◽  
Centrifugal Compressor ◽  
Optimization Techniques ◽  
Design System ◽  
Design Modification ◽  
One Dimensional ◽  
Multi Objective ◽  
Direct Design ◽  
Multistage Compressor ◽  
The Impact

Automatic optimization techniques have been used in recent years to facilitate more rapid analyses of different design options with multiple performance objectives. Typically, this process has been used during new product development. In this paper, a design system is presented, which enables the multipoint, multi-objective optimization of the centrifugal compressor stage aerodynamic components. Moreover, it is applied to a design modification of a multistage compressor, during the manufacturing cycle, for risk mitigation. The system is based on the application of the Isight code for coupling of one dimensional direct design and analysis with multi-objective genetic algorithms, design of experiment, and response surface method. The design system was applied to a redesign of the diffuser, crossover, and return channel of two stages in a multistage compressor. The geometry parameterization is performed by a one dimensional analysis method where the diffuser width, crossover inlet and exit width and associated inner and outer radii, are used to describe the meridional flow path while holding the return vane geometry unchanged. Centrifugal compressor performance parameters, such as polytropic head and efficiency at the client rated point, head rise to surge, and choke flow capacity are evaluated during the optimization process. The example confirmed the validity of the system to perform the optimization of turbomachine components in a time efficient manner to meet production schedule. The system also allowed for a sensitivity analysis of the impact of geometry parameters on the aerodynamic performance, contributing to the development of guidelines for manufacturers to design new products and mitigate the performance risk on test floor.

A Strategy for Multi-Point Compressor Blading Using Multi-Objective Optimization

2012 ◽  
Author(s):  
Alireza Fathi ◽  
Abdollah Shadaram ◽  
Mohammad Alizadeh
Keyword(s):  
Incidence Angle ◽  
Optimization Algorithms ◽  
Optimization Techniques ◽  
Design System ◽  
Design Calculation ◽  
Blade Design ◽  
Objective Functions ◽  
Multi Objective ◽  
First Case ◽  
Through Flow

This paper introduces a framework to perform a multi-objective multipoint aerodynamic optimization for an axial compressor blade. This framework considers through-flow design requirements and mechanical and manufacturing constraints. Typically, components of a blade design system include geometry generation tools, optimization algorithms, flow solvers, and objective functions. In particular, optimization algorithms and objective functions are tuned to reduce blade design calculation cost and to match designed blade performance to the through flow design criteria and mechanical and manufacturing constrains. In the present study, geometry parameters of blade are classified to three categories. For each category, a distinct optimization loop is applied. In outer loop, Gradient-based optimization techniques are used to optimize parameters of the second category and a two-dimensional compressible viscous flow code is used to simulate the cascade fluid flow. Surface curvature optimization is carried out in inner loop, and its objective function is defined by integrating the normalized curvature and curvature slope. The genetic algorithm is used to optimize the parameters in the interior loop. To highlight the capabilities of the design method and to develop design know-how, an initial profile is optimized with three different design philosophies. The highest performance improvement in the first case is 15% reduction in loss at design incidence angle. In the second case, 16.5% increase in allowable incidence angle range, improves blade’s performance at off design conditions.

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.

Multi-objective vehicle optimization: Comparison of combustion engine, hybrid and electric powertrains

2019 ◽  
Vol 234 (2-3) ◽  
pp. 469-487 ◽  
Author(s):  
Nikola Holjevac ◽  
Federico Cheli ◽  
Massimiliano Gobbi
Keyword(s):  
Electric Vehicle ◽  
New Technologies ◽  
Combustion Engine ◽  
Market Competition ◽  
Optimization Techniques ◽  
Power Sources ◽  
Main Design ◽  
Multi Objective ◽  
Design Variables ◽  
The Impact

The use of optimization techniques has been extensively adopted in vehicle design and with the increasing complexity of systems, especially with the introduction of new technologies, it plays an even more significant role. Market competition, stringent mandatory emission regulations and the need for a future sustainable mobility have raised questions over conventional vehicles and are pushing toward new cleaner and eco-friendly solutions. Fulfilling this target without sacrificing the other vehicle’s requirements leads to extremely challenging tasks for vehicle designers. The use of virtual prototyping emerges as a possible breakthrough allowing to rapidly assess the effect of design changes and the impact of new technologies. The study presented in this work provides a suitable approach to compare different vehicle powertrain architectures through optimization techniques and deploying model-based simulation to rapidly assess vehicle performances. The vehicle model is defined at the components level through scalable models obtained from based on detailed simulation. An optimal energy management is applied to the power sources and transmission gear shifting. The optimization technique consider the main design variables of the various components including vehicle chassis and extensively exploits the design space. The multi-objective optimization considers vehicle’s consumption, emission, range, longitudinal and lateral dynamics, costs and further performances to comprehensively assess the vehicle. The results allow to compare four different powertrain architectures: combustion engine vehicle, hybrid electric vehicle with parallel and series configuration, and battery electric vehicle. The results allows furthermore to identify technological limitations and conflicts among the different objectives. A critical analysis over the main design variables allows to identify the more suitable values and in particular, for combustion engine, gearbox and electric traction drive detailed comparisons are provided.

scholarly journals Improving the usability of climate indicator visualizations through diagnostic design principles

2021 ◽  
Vol 166 (3-4) ◽  
Author(s):  
Michael D. Gerst ◽  
Melissa A. Kenney ◽  
Irina Feygina
Keyword(s):  
Design Guidelines ◽  
Party Affiliation ◽  
Abstract Concepts ◽  
Design Modification ◽  
Climate Indicators ◽  
Present Complex ◽  
Control Versus ◽  
Climate Indicator ◽  
Political Party Affiliation ◽  
The Impact

AbstractVisual climate indicators have become a popular way to communicate trends in important climate phenomena. Producing accessible visualizations for a general audience is challenging, especially when many are based on graphics designed for scientists, present complex and abstract concepts, and utilize suboptimal design choices. This study tests whether diagnostic visualization guidelines can be used to identify communication shortcomings for climate indicators and to specify effective design modifications. Design guidelines were used to diagnose problems in three hard-to-understand indicators, and to create three improved modifications per indicator. Using online surveys, the efficacy of the modifications was tested in a control versus treatment setup that measured the degree to which respondents understood, found accessible, liked, and trusted the graphics. Furthermore, we assessed whether respondents’ numeracy, climate attitudes, and political party affiliation affected the impact of design improvements. Results showed that simplifying modifications had a large positive effect on understanding, ease of understanding, and liking, but not trust. Better designs improved understanding similarly for people with different degrees of numerical capacity. Moreover, while climate skepticism was associated with less positive subjective responses and greater mistrust toward climate communication, design modification improved understanding equally for people across the climate attitude and ideological spectrum. These findings point to diagnostic design guidelines as a useful tool for creating more accessible, engaging climate graphics for the public.

scholarly journals The effect of the outlet angle β2 on the thermomechanical behavior of a centrifugal compressor blade

2020 ◽  
Vol 29 (1) ◽  
pp. 1-8
Author(s):  
Ahmed Allali ◽  
Sadia Belbachir ◽  
Ahmed Alami ◽  
Belhadj Boucham ◽  
Abdelkader Lousdad
Keyword(s):  
Mechanical Behavior ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Complex Form ◽  
Compressor Blade ◽  
Stress Fields ◽  
The Finite Element Method ◽  
Mechanical Fatigue ◽  
Outlet Angle ◽  
The Impact

AbstractThe objective of this work lies in the three-dimensional study of the thermo mechanical behavior of a blade of a centrifugal compressor. Numerical modeling is performed on the computational code "ABAQUS" based on the finite element method. The aim is to study the impact of the change of types of blades, which are defined as a function of wheel output angle β2, on the stress fields and displacements coupled with the variation of the temperature.This coupling defines in a realistic way the thermo mechanical behavior of the blade where one can note the important concentrations of stresses and displacements in the different zones of its complex form as well as the effects at the edges. It will then be possible to prevent damage and cracks in the blades of the centrifugal compressor leading to its failure which can be caused by the thermal or mechanical fatigue of the material with which the wheel is manufactured.

Altitude Effects on the Performance of Small Radial Turbomachinery: Part I — Compressor Impellers

2016 ◽  
Author(s):  
Dries Verstraete ◽  
Kjersti Lunnan
Keyword(s):  
Reynolds Number ◽  
Performance Analysis ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
Unmanned Aircraft ◽  
Good Match ◽  
One Dimensional ◽  
Design Changes ◽  
Current Article ◽  
The Impact

Small unmanned aircraft are currently limited to flight ceilings below 20,000 ft due to the lack of an appropriate propulsion system. One of the most critical technological hurdles for an increased flight ceiling of small platforms is the impact of reduced Reynolds number conditions at altitude on the performance of small radial turbomachinery. The current article investigates the influence of Reynolds number on the efficiency and pressure ratio of two small centrifugal compressor impellers using a one-dimensional meanline performance analysis code. The results show that the efficiency and pressure ratio of the 60 mm baseline compressor at the design rotational speed drops with 6–9% from sea-level to 70,000 ft. The impact on the smaller 20 mm compressor is slightly more pronounced and amounts to 6–10%. Off-design changes at low rotational speeds are significantly higher and can amount to up to 15%. Whereas existing correlations show a good match for the efficiency drop at the design rotational speed, they fail to predict efficiency changes with rotational speed. A modified version is therefore proposed.

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