Burmester Field Envelopes for Multiple Design Parameters

1998 ◽  
Author(s):  
John R. Mlinar ◽  
Arthur G. Erdman
Keyword(s):  
Design Parameter ◽  
Design Parameters ◽  
Design Variables ◽  
Selection Of ◽  
Envelope Theory

Abstract The Burmester field is the area swept by a Burmester curve as one or more of the design variables change. This paper presents the envelope of the Burmester field for more than one design parameter. It is shown that the envelope consists of various segments. These segments are found to be portions of Burmester curves and curves found using envelope theory. A two- and three-parameter example are provided and discussed. The application of the Burmester field concept to the design of linkages is also discussed. This includes the limitations on the selection of the second dyad.

Selection of One-Dimensional Design Parameter ‘Reaction Degree’ for 1st Stage of a Cooled Gas Turbine

2012 ◽  
Author(s):  
Hina Noor ◽  
Magnus Genrup ◽  
Torsten Fransson
Keyword(s):  
Mass Flow ◽  
Design Parameter ◽  
Design Tool ◽  
Performance Estimation ◽  
Design Parameters ◽  
Flow Angle ◽  
One Dimensional ◽  
And Performance ◽  
Reaction Degree ◽  
Selection Of

The recommendations available today in open literature for the choice of design parameter such as flow coefficient, stage loading and reaction degree incorporates mainly the influence of aerodynamics loss on efficiency. However, it is difficult to find the recommendation relating the influence of not only the aerodynamics loss but also cooling mass flow and cooling losses on varying most influential design parameters. In this paper, preliminary design and performance guidelines are presented for a cooled turbine stage using the 1D design tool LUAXT. The intention is to provide recommendations on the selection of design parameters, mainly reaction degree, which is found to be highly influenced by not only the aerodynamics loss but also the cooling mass flow and cooling loss such as in 1st stage of a High Pressure Turbines (HPT). The One-Dimensional (1D) design methods used to perform this task are verified and validated against experimental test data. A comparison of different loss models has been performed to provide most accurate outcomes for certain tested ranges. Based on the outcomes of this study, ‘Craig & Cox’ loss model has been considered to perform subsequent investigations for HPT design and performance estimation while formulating a parametric study. From this study, the design recommendations for the selection of performance parameter reaction degree are developed for cooled turbines. The results shows that for a HPT 1st stage, the recommended reaction degree range of 0.20 to 0.37 seems to provide the optimum stage design when chosen for stage loading in between 1.40 to 1.80 along with the stator exit flow angle in range of 74° to 78°.

scholarly journals About eigen sensitivity analysis of mechanical structures

2013 ◽  
Vol 40 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Natasa Trisovic
Keyword(s):  
Order Approximation ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Fe Model ◽  
Design Variables ◽  
Structural Reanalysis ◽  
First Order Approximation ◽  
Derivatives Of ◽  
Selection Of ◽  
Modal Method

Several methods for a calculation of derivatives of eigenvectors with respect to design parameters are described here. These are the finite-difference method, the modal method, a modified modal method, Nelson's method, an improved first-order approximation of eigenvalues and eigenvectors and an iterative method. By combining the other structural reanalysis techniques and one of these sensitivity methods, it is possible to enhance the efficiency and the accuracy of structural optimization techniques for determining the optimum condition of mechanical structure specified by an analyst. The sensitivity approach is based on the prior selection of updating parameters (design variables) in the initial FE model.

A General Design Program Based on Genetic Algorithms With Applications

1995 ◽  
Author(s):  
Cornelia M. Kalker ◽  
Marcel F. Offermans
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Optimal Solution ◽  
Problem Definition ◽  
Design Parameters ◽  
Interactive Program ◽  
Design Variables ◽  
Design Program ◽  
Standard Values ◽  
Selection Of

Abstract When designing constructions, a number of decisions must be made as to types of constructions, values of geometric or other design variables, choices of materials and selection of standard values. These decisions are often based on conflicting requirements. In the present paper, a genetic algorithm is proposed for finding an optimal solution for those problems. The genetic algorithm has been implemented in an interactive program. The problem is formulated in terms of design parameters and relations (equalities, inequalities or procedures) between them. This information is parsed by a preprocessor and results in a problem definition that can be optimized with the genetic algorithm. During the optimization, the process can be followed and controlled by the designer. The values of all design parameters can be monitored, search intervals can be changed and parameters of the algorithm modified. All this speeds up the algorithm and improves the designer’s insight in the problem. As an example the design of navigation locks is treated.

Optimization of Catenary Risers

1999 ◽  
Vol 121 (2) ◽  
pp. 90-94 ◽  
Author(s):  
C. M. Larsen ◽  
T. Hanson
Keyword(s):  
Water Depth ◽  
Equivalent Stress ◽  
Nonlinear Function ◽  
Design Parameters ◽  
Design Variables ◽  
Function Design ◽  
General Constraints ◽  
Riser Design ◽  
Selection Of

This paper describes how the design of a catenary riser can be formulated as an optimization problem by using riser costs as the criteria function, design requirements in terms of maximum allowable stress and buckling capacity as constraints, and riser dimensions as free variables. The theory has been implemented in a computer program that can generate an optimized riser design for given design parameters such as water depth, diameter, pressure, and platform excursions. The developed software consists of a conventional program for two-dimensional riser analysis and a set of standard routines to minimize a nonlinear function subjected to general constraints. A case study where design parameters and requirements have been varied is also presented. The importance of buckling versus allowable equivalent stress as the most critical constraint has been investigated for varying water depth. The Conclusion of this work is that optimization is a useful tool for riser design, and that the proposed strategy for selection of design variables and constraints will enable an engineer to identify designs with minimum costs in an efficient way.

Effiecency criterion for selection of design parameters of aerospace system

2016 ◽  
Vol 22 (2(99)) ◽  
pp. 48-51
Author(s):  
D.S. Kalynychenko ◽  
◽  
Ye.Yu. Baranov ◽  
M.V. Poluian ◽  
◽  
...  
Keyword(s):  
Design Parameters ◽  
Selection Of

Color Trend Analysis using Machine Learning with Fashion Collection Images

2021 ◽  
pp. 0887302X2199594
Author(s):  
Ahyoung Han ◽  
Jihoon Kim ◽  
Jaehong Ahn
Keyword(s):  
Machine Learning ◽  
Trend Analysis ◽  
Image Data ◽  
Fashion Industry ◽  
Color Palette ◽  
Web Scraping ◽  
Design Variables ◽  
Sales Organizations ◽  
Fashion Designers ◽  
Selection Of

Fashion color trends are an essential marketing element that directly affect brand sales. Organizations such as Pantone have global authority over professional color standards by annually forecasting color palettes. However, the question remains whether fashion designers apply these colors in fashion shows that guide seasonal fashion trends. This study analyzed image data from fashion collections through machine learning to obtain measurable results by web-scraping catwalk images, separating body and clothing elements via machine learning, defining a selection of color chips using k-means algorithms, and analyzing the similarity between the Pantone color palette (16 colors) and the analysis color chips. The gap between the Pantone trends and the colors used in fashion collections were quantitatively analyzed and found to be significant. This study indicates the potential of machine learning within the fashion industry to guide production and suggests further research expand on other design variables.

scholarly journals Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Javaid Ahmad ◽  
Shaohong Cheng ◽  
Faouzi Ghrib
Keyword(s):  
Analytical Model ◽  
Design Parameters ◽  
Reference Base ◽  
Cable Network ◽  
Cable Networks ◽  
Modal Behavior ◽  
Stiffness And Damping ◽  
Main Cables ◽  
The Impact ◽  
Selection Of

Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

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