Solution of the wedge entry problem by numerical conformal mapping

1972 ◽  
Vol 56 (1) ◽  
pp. 173-192 ◽  
Author(s):  
O. F. Hughes
Keyword(s):  
Conformal Mapping ◽  
Functional Dependence ◽  
Mapping Function ◽  
Computer Method ◽  
Analytic Method ◽  
Inviscid Fluid ◽  
Numerical Conformal Mapping ◽  
Method Of Solution ◽  
Entire Flow

An accurate quasi-analytic method of solution is presented for the classical hydrodynamics problem of the constant-velocity entry of a prismatic wedge into a weightless incompressible inviscid fluid. The method uses the Wagner function W, which reduces the problem to the determination of a mapping function Λ = [Lscr ](W) for the hodograph. [Lscr ](W) is constructed by using the hodograph for an unsymmetric diamond together with a modifying or ‘preparatory’ trans-formation. A computer method of conformal mapping is developed and is used to obtain this latter transformation. Results are presented for the case of a 90° wedge and show that the solution is both more accurate than previous solutions, having an error of less than 1 %, and more complete, as it portrays the entire flow field and furnishes information about the functional dependence among the variables.

scholarly journals Improving the Accuracy of the Charge Simulation Method for Numerical Conformal Mapping

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Fuming Lai ◽  
Yingzi Wang ◽  
Yibin Lu ◽  
Jian Wang
Keyword(s):  
Conformal Mapping ◽  
Dynamic System ◽  
Mapping Function ◽  
Constraint Equation ◽  
Simulation Method ◽  
Conformal Radius ◽  
Kutta Method ◽  
Charge Simulation Method ◽  
Numerical Conformal Mapping ◽  
Runge Kutta Method

In this paper, we present a method to improve the accuracy of the charge simulation method for numerical conformal mapping. The method constructs the constraint equation by using the charge simulation method. The charges and the conformal radius are computed by using the Runge-Kutta method based on the dynamic system of the constraint equation. By using this method, we can obtain new approximated conformal mapping function and improve the accuracy of numerical conformal mapping compared to the charge simulation method for numerical conformal mapping proposed by Amano. Furthermore, the corresponding numerical results are shown to illustrate the performance of the proposed method.

Solution of Some Problems in Bending of Thin Clamped Plates by Means of the Method of Muskhelishvili

1957 ◽  
Vol 24 (2) ◽  
pp. 295-298
Author(s):  
L. I. Deverall
Keyword(s):  
Conformal Mapping ◽  
Mapping Function ◽  
Elliptic Functions ◽  
Transverse Load ◽  
Rectangular Plates ◽  
Convergence Properties ◽  
Clamped Plate ◽  
Central Maximum ◽  
Method Of Solution ◽  
Square Plate

Abstract In this paper, the complex variable method of N. I. Muskhelishvili is applied to the problem of bending for small deflections of a thin, isotropic, homogeneous, clamped plate with transverse load. The functional equation involved in Muskhelishvili’s method is solved by means of series expansions. The necessary conformal mapping functions are found from the Schwarz-Christoffel formula or expansion of elliptic functions. For uniformly loaded square and rectangular plates, the central (maximum) deflection obtained by the method of Muskhelishvili is compared to the corresponding deflections obtained by other methods. Deflections for the square plate are given for three and five terms, respectively, of the series expansion of the conformal mapping function in order to estimate convergence properties of the method of solution. The solution for a uniformly loaded clamped plate of equilateral triangular planform is also discussed. Central deflection for this case is given.

scholarly journals RESEARCH INTO THE METHODS OF ANALYSING THE PRODUCTIVITY INDICATORS OF TRANSPORT TERMINALS

Transport ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 192-199 ◽  
Author(s):  
Ilona Jaržemskienė
Keyword(s):  
Comparative Analysis ◽  
Functional Dependence ◽  
Data Envelopment ◽  
Analysis Method ◽  
Accurate Evaluation ◽  
Feasible Alternative ◽  
Productivity Indicators ◽  
Insight Into ◽  
Regressive Analysis

The measurement of terminal productivity is the issue of extreme importance to both terminal owners and management and customers. As the sector of transport is highly intensive in terms of investments into the infrastructure, the productivity of a terminal may play a crucial role in competing with other terminals. Productivity is defined in terms of inputs and output. The majority of the available studies, wherein this issue is addressed, are generally focused on the determination of functional dependence between inputs and output using the method of regressive analysis. The present article provides an insight into the Data Envelopment Analysis method as a tool for measuring productivity. This technique enables a rather accurate evaluation of terminal productivity by means of comparative analysis, which, in fact, appears to be the only feasible alternative in cases where statistic data required for performing regressive analysis is lacking.

Determination of global kinetic parameters by optimization procedure using burning velocity measurements

2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev
Keyword(s):  
Kinetic Parameters ◽  
Equivalence Ratio ◽  
Reaction Rate ◽  
Functional Dependence ◽  
Burning Velocity ◽  
Optimization Procedure ◽  
Optimal Parameters ◽  
Velocity Measurements ◽  
Equilibrium Calculations

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.

scholarly journals Stored Energy of Plastic Deformation in Tube Bending Processes

2013 ◽  
Vol 18 (1) ◽  
pp. 235-248 ◽  
Author(s):  
Z. Śloderbach ◽  
J. Pająk
Keyword(s):  
Plastic Deformation ◽  
Service Life ◽  
Plastic Strain ◽  
Analytic Method ◽  
Stored Energy ◽  
Tube Bending ◽  
Cold Bending ◽  
Tension And Compression

The paper presents an aproximate analytic method for determination of the stored energy of plastic deformation during cold bending of metal tubes at bending machines. Calculations were performed for outer points of the tube layers subjected to tension and compression (the points of maximum strains). The percentage of stored energy related to the plastic strain work was determined and the results were presented in graphs. The influence and importance of the stored energy of plastic deformation on the service life of pipeline bends are discussed.

scholarly journals Metode Penentuan Akad pada Transaksi Uang Elektronik

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Sofwan Hadikusuma
Keyword(s):  
Qualitative Research ◽  
Analytic Method ◽  
Electronic Money ◽  
Secondary Sources

This paper is intended to explain the methods used by experts in determining the contracts used in electronic money transactions. The focus of this paper is not only on contract determination, but how a contract is embedded in electronic money transactions. This research is a qualitative research wich uses descriptive-analytic method. Data obtained from secondary sources such as books, journals, websites, and relevant documentation. The results showed that in principle, there are two methods in determining the contract in a muamalah transaction. The first method uses the editorial approach (words) which focuses on the contract words, and the second uses the substance (meaning) approach which considers the contract based on the aims and objectives of the contract as seen from the form of the agreement as well as the rights and obligations obtained by each party. Regarding the topic of discussion, it can be concluded that the determination of the contract in electronic money transactions uses a meaningful approach. That because the consideration used in determining the electronic money contract is based on the form of the transaction that occurs between the parties, not just the existing words.

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