Multilevel Optimization Techniques for Aircraft

1993 ◽  
pp. 25-54
Author(s):  
Trent R. Logan ◽  
Frank F. Abdi ◽  
Jaroslaw Sobieszczanski-Sobieski
Keyword(s):  
Optimization Techniques ◽  
Multilevel Optimization

COMPLEX METHODOLOGY FOR CALCULATING THE OPTIMAL PARAMETERS OF THE HEAT RECOVERY SYSTEM OF A BOILER PLANT

2017 ◽  
Author(s):  
Nataliia Fialko ◽  
◽  
Alla Stepanova ◽  
Raisa Navrodskaia ◽  
Svetlana Shevchuk ◽  
...  
Keyword(s):  
Heat Recovery ◽  
Optimization Techniques ◽  
Planning Theory ◽  
Design Parameters ◽  
Optimal Parameters ◽  
Multilevel Optimization ◽  
Boiler Plant ◽  
Experimental Planning ◽  
Recovery System ◽  
Heat Recovery System

The results of optimizing the parameters of the heat recovery system of a boiler plant designed to heat return water are presented. The feasibility of using a technique that combines methods of exergy analysis experimental planning theory and multilevel optimization to optimize plant parameters is analyzed. It is emphasized that the efficiency of heat recovery systems optimized using the above technique is 2-3% higher than the efficiency of systems optimized using other optimization techniques. In addition, the specified method allows to take into account a significant part of the technical losses in the heat recovery system and to optimize a large number of parameters. The main stages of a comprehensive methodology are given. At each stage, the above methods are used to develop mathematical models and obtain dependences of exergy efficiency criteria on the parameters of the heat recovery system. The results of calculating the optimum values of operating and design parameters for the considered heat recovery system of the boiler unit are presented.

A Multiscale Design Methodology for Hierarchical Systems With Random Field Uncertainty

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Wei Chen ◽  
Xiaolei Yin ◽  
Sanghoon Lee ◽  
Wing Kam Liu
Keyword(s):  
Random Field ◽  
Design Methodology ◽  
Material Design ◽  
Optimization Techniques ◽  
Computational Techniques ◽  
Hierarchical Systems ◽  
Multilevel Optimization ◽  
Product Systems ◽  
Multiple Length Scales ◽  
Hierarchical Multiscale

A multiscale design methodology is proposed for hierarchical material and product systems with random field uncertainty that propagates across multiple length scales. Using the generalized hierarchical multiscale decomposition pattern in multiscale modeling, a set of computational techniques is developed to manage the system complexity. Design of experiments and metamodeling strategies are proposed to manage the complexity of propagating random field uncertainty through three generalized levels of transformation: the material microstructure random field, the material property random field, and the probabilistic product performance. Multilevel optimization techniques are employed to find optimal design solutions at individual scales. A hierarchical multiscale design problem that involves a two-scale (submicro- and microscales) material design and a macroscale product (bracket) design is used to demonstrate the applicability and benefits of the proposed methodology.

scholarly journals Multilevel Optimization for Dense Motion Estimation

2012 ◽  
Author(s):  
El Mostafa Kalmoun ◽  
Azizan Saaban ◽  
Haslinda Ibrahim ◽  
Razamin Ramli ◽  
Zurni Omar
Keyword(s):  
Motion Estimation ◽  
Global Optimum ◽  
Optimization Techniques ◽  
Multilevel Optimization ◽  
Reliable Technique ◽  
Flow Estimation ◽  
Optical Flow Estimation ◽  
Self Study ◽  
Scientists And Engineers ◽  
Basic Concepts

This monograph offers design for fast and reliable technique in the dense motion estimation. This Multilevel Optimization for Dense Motion Estimation work blends both theory and applications to equip reader with an understanding of basic concepts necessary to apply in solving dense motion in a sequence of images. Illustrating well-known variation models for dealing with optical flow estimation, this monograph introduces variation models with applications. A host of variation models are outlines such as Horn-Schunck model, Contrast Invariation Models and Models for Large Displacement. Special attention is also given to multilevel optimization techniques namely multiresolution and multigrid methods to improve the convergence of the global optimum when compared to using only one level resolution in the context of computer vision. This monograph is a robust resource that provides insightful introduction to the field of image processing with its theory and applications. Overall, Multilevel Optimization for Dense Motion Estimation is highly recommended for scientists and engineers for an excellent choice for references and self-study.

scholarly journals A Strategy for Reducing Turnaround Time in Design Optimization Using a Distributed Computer System

1988 ◽  
Author(s):  
K. C. Young ◽  
S. L. Padula ◽  
J. L. Rogers
Keyword(s):  
Design Optimization ◽  
Engineering Design ◽  
Data Flow ◽  
Turnaround Time ◽  
Optimization Techniques ◽  
Multilevel Optimization ◽  
Design Problems ◽  
Distributed Computer System ◽  
Engineering Design Problems ◽  
Structural Design Optimization

Abstract There is a need to explore methods for reducing lengthly computer turnaround or clock time associated with engineering design problems. Different strategies can be employed to reduce this turnaround time. One strategy is the use of a supercomputer, which can be costly in terms of hardware acquisition and software modification. Another strategy is to run validated analysis software on a network of existing smaller computers so that portions of the computation can be done in parallel. This paper focuses on the implementation of this second strategy using two types of problems. The first type is a traditional structural design optimization problem, which is characterized by a simple data flow and a complicated analysis. The second type of problem uses an existing computer program designed to study multilevel optimization techniques. This problem is characterized by complicated data flow and a simple analysis. The paper shows that distributed computing can be a viable means for reducing computational turnaround time for engineering design problems that lend themselves to decomposition. Parallel computing can be accomplished with a minimal cost in terms of hardware and software.

Review on the aerodynamics of intermediate compressor duct

2020 ◽  
Vol 14 (4) ◽  
pp. 7446-7468
Author(s):  
Manish Sharma ◽  
Beena D. Baloni
Keyword(s):  
High Pressure ◽  
Pressure Loss ◽  
Flow Analysis ◽  
Outer Wall ◽  
Optimization Techniques ◽  
Optimum Pressure ◽  
Research Areas ◽  
Static Pressure Distribution ◽  
High Pressure Compressor ◽  
Pressure Compressor

In a turbofan engine, the air is brought from the low to the high-pressure compressor through an intermediate compressor duct. Weight and design space limitations impel to its design as an S-shaped. Despite it, the intermediate duct has to guide the flow carefully to the high-pressure compressor without disturbances and flow separations hence, flow analysis within the duct has been attractive to the researchers ever since its inception. Consequently, a number of researchers and experimentalists from the aerospace industry could not keep themselves away from this research. Further demand for increasing by-pass ratio will change the shape and weight of the duct that uplift encourages them to continue research in this field. Innumerable studies related to S-shaped duct have proven that its performance depends on many factors like curvature, upstream compressor’s vortices, swirl, insertion of struts, geometrical aspects, Mach number and many more. The application of flow control devices, wall shape optimization techniques, and integrated concepts lead a better system performance and shorten the duct length.  This review paper is an endeavor to encapsulate all the above aspects and finally, it can be concluded that the intermediate duct is a key component to keep the overall weight and specific fuel consumption low. The shape and curvature of the duct significantly affect the pressure distortion. The wall static pressure distribution along the inner wall significantly higher than that of the outer wall. Duct pressure loss enhances with the aggressive design of duct, incursion of struts, thick inlet boundary layer and higher swirl at the inlet. Thus, one should focus on research areas for better aerodynamic effects of the above parameters which give duct design with optimum pressure loss and non-uniformity within the duct.

Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima
Keyword(s):  
Finite Element ◽  
New Technologies ◽  
Computational Mechanics ◽  
Design Procedure ◽  
Side Wall ◽  
Rolling Resistance ◽  
Optimization Techniques ◽  
Stress Strain ◽  
Element Analysis ◽  
Crown Shape

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

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