Design and Optimization of Composite Rectangular Fins Using the Relative Inverse Thermal Admittance

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Juan P. Luna–Abad ◽  
Francisco Alhama
Keyword(s):  
Heat Conduction ◽  
Composite Layer ◽  
Optimization Process ◽  
Convective Conditions ◽  
Design And Optimization ◽  
Optimum Geometry ◽  
Relative Inverse ◽  
Universal Graphs

The concept of relative inverse admittance applied to composite fins optimization in the case of longitudinal rectangular fins under 2D heat conduction is presented in this work. Here, different values for convective conditions at the fin and composite layer surfaces are used and the influence of the kc/kf ratio and composite thickness in optimum geometry is determined. The optimization process is carried out through universal graphs in which the range of parameters covers most of the practical cases a designer will find. Relative inverse admittance is applied in a general form and emerges as an easily used tool for optimizing composite fins.

scholarly journals The use of relative inverse thermal admittance for the characterization and optimization of fin-wall assemblies

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 151-160 ◽  
Author(s):  
Juan Luna-Abad ◽  
Francisco Alhama ◽  
Antonio Campo
Keyword(s):  
Heat Transfer ◽  
Heat Dissipation ◽  
Fundamental Parameter ◽  
Optimum Thickness ◽  
Convective Conditions ◽  
Optimum Geometry ◽  
Relative Inverse ◽  
Universal Graphs ◽  
Wall Assembly ◽  
Convective Fin

The concept of relative inverse thermal admittance applied to the convective fin-wall assembly optimization of longitudinal rectangular fins under 2-D heat conduction is presented in this work. Since heat transfer at the fin tip is taken into account, it is not always possible to optimize the above cited geometry. This is relevant in optimization processes and because of this has been displayed in several graphs. Here, different values for convective conditions at the fin and wall surfaces are used and the influence of the hw/hf ratio in optimum geometry is determined. The fin effectiveness is used as the fundamental parameter to prove that the fin is fulfilling the objective of increasing heat dissipation. Once the optimum thickness has been obtained, the Biot number is easily calculated and the fin effectiveness for an isolated fin and the fin-wall assembly can be determined graphically. The optimization process is carried out through a set of universal graphs in which the range of parameters covers most of the practical cases a designer will find. The concept of relative inverse thermal admittance is applied in a general form and emerges as an easy used tool for optimizing fin-wall assemblies.

One-Dimensional Transient Heat Conduction in Composite Living Perfuse Tissue

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
S. M. Becker
Keyword(s):  
Heat Conduction ◽  
Initial Conditions ◽  
Separation Of Variables ◽  
Composite Layer ◽  
Circulatory System ◽  
Transient Heat Conduction ◽  
Bioheat Equation ◽  
Perfusion Rate ◽  
One Dimensional ◽  
Perfuse Tissue

Modeling the conduction of heat in living tissue requires the consideration of sudden spatial discontinuities in property values as well as the presence of the body's circulatory system. This paper presents a description of the separation of variables method that results in a remarkably simple solution of transient heat conduction in a perfuse composite slab for which at least one of the layers experiences a zero perfusion rate. The method uses the natural analytic approach and formats the description so that the constants of integration of each composite layer are expressed in terms of those of the previous layer's eigenfunctions. This allows the solution to be “built” in a very systematic and sequential manner. The method is presented in the context of the Pennes bioheat equation for which the solution is developed for a system composed of any number of N layers with arbitrary initial conditions.

Evolutionary Multi-Agent Systems: An Adaptive Approach to Optimization in Dynamic Environments

2008 ◽  
Author(s):  
Lindsay Hanna ◽  
Jonathan Cagan
Keyword(s):  
Organizational Structure ◽  
Engineering Design ◽  
Dynamic Environments ◽  
Optimization Process ◽  
Multi Agent Systems ◽  
Design And Optimization ◽  
Solution Strategies ◽  
Engineering Design Problems ◽  
Potential Applications ◽  
Multi Agent

This paper explores the ability of a team of autonomous software agents to be effective in unknown and changing optimization environments by evolving to use the most successful algorithms at the points in the optimization process where they will be the most effective. We present the core framework and methodology which has potential applications in layout, scheduling, manufacturing, and other engineering design areas. The communal agent team organizational structure employed allows cooperation of agents through the products of their work and creates an ever changing set of individual solutions for the agents to work on. In addition, the organizational structure allows the framework to be adaptive to changes in the design space that occur during the optimization process — making our approach extremely flexible to the kinds of dynamic environments encountered in engineering design problems. An evolutionary approach is used, but evolution occurs at the strategic, rather than solution level — where the strategies of agents in the team (the decisions for picking, altering, and inserting a solution) evolve over time. As an application of this approach, individual solutions are tours in the familiar combinatorial optimization problem of the traveling salesman. With a constantly changing set of these tours, the team, each agent running a different solution strategy, must evolve to apply the solution strategies which are most useful given the set at any point in the process. As a team, the evolutionary agents produce better solutions than any individual algorithm. We discuss the extensions to our preliminary work that will make our framework highly useful to the design and optimization community.

scholarly journals Small Wind Turbine Blade Design and Optimization

Symmetry ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 18 ◽  
Author(s):  
Hani Muhsen ◽  
Wael Al-Kouz ◽  
Waqar Khan
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Optimization Process ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Horizontal Axis Wind Turbine ◽  
Design And Optimization ◽  
Low Wind Speed ◽  
Low Performance ◽  
Turbine Blade Design

This work aims at designing and optimizing the performance of a small Horizontal-Axis-Wind-Turbine to obtain a power coefficient (CP) higher than 40% at a low wind speed of 5 m/s. Two symmetric in shape airfoils were used to get the final optimized airfoil. The main objective is to optimize the blade parameters that influence the design of the blade since the small turbines are prone to show low performance due to the low Reynolds number as a result of the small size of the rotor and the low wind speed. Therefore, the optimization process will select different airfoils and extract their performance at the design conditions to find the best sections which form the optimal design of the blade. The sections of the blade in the final version mainly consist of two different sections belong to S1210 and S1223 airfoils. The optimization process goes further by investigating the performance of the final design, and it employs the blade element momentum theory to enhance the design. Finally, the rotor-design was obtained, which consists of three blades with a diameter of 4 m, a hub of 20 cm radius, a tip-speed ratio of 6.5 and can obtain about 650 W with a Power coefficient of 0.445 at a wind-speed of 5.5 m/s, reaching a power of 1.18 kW and a power coefficient of 0.40 at a wind-speed of 7 m/s.

Optimum Design of Pressure Vessels Using Hybrid HGP and Genetic Algorithm

2017 ◽  
Author(s):  
Khalid M. Abd El-Aziz ◽  
Sayed M. Metwalli
Keyword(s):  
Optimum Design ◽  
Research Work ◽  
Stress Constraints ◽  
Cylindrical Part ◽  
Pressure Vessels ◽  
Design And Optimization ◽  
Design Charts ◽  
Optimum Geometry ◽  
Asme Code ◽  
Geometrical Dimensions

This paper presents research work about the design and optimization of pressure vessels using Hybrid Heuristic Gradient Projection (HGP), Sequential Quadratic Programming (SQP) and Genetic Algorithms (GA). The design is concerned with the pressure loading conditions, intended internal utility volume, geometrical dimensions and the induced stresses. Cylindrical pressure vessels with hemispherical ends are considered. They are required to hold a definite volume under a specific pressure. The thicknesses of each hemispherical part and the cylindrical part satisfy the recommended ASME code. The design also satisfies allowable stress constraints. The design multi-objectives are to generate the optimum geometry to satisfy required specifications, performance and cost requirements. A developed HGP, SQP and GA algorithms are utilized to perform the optimization. The efficiency of the procedure is indicated and the optimum results in the form of optimum design charts are presented.

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