A One-Dimensional Model for Monolithic Converter: Numerical Simulation and Experimental Verification of Conversion and Thermal Responses for Two-Stroke Engine

1991 ◽  
Author(s):  
Dario Cundari ◽  
Marco Nuti
Keyword(s):  
Numerical Simulation ◽  
Experimental Verification ◽  
Dimensional Model ◽  
One Dimensional ◽  
Stroke Engine

Numerical simulation of two-dimensional fins using the meshless local Petrov – Galerkin method

2020 ◽  
Vol 37 (8) ◽  
pp. 2913-2938
Author(s):  
Rajul Garg ◽  
Harishchandra Thakur ◽  
Brajesh Tripathi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Experimental Investigation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Content Type ◽  
One Dimensional ◽  
Mlpg Method ◽  
Convection Model ◽  
Good Agreement

Purpose The study aims to highlight the behaviour of one-dimensional and two-dimensional fin models under the natural room conditions, considering the different values of dimensionless Biot number (Bi). The effect of convection and radiation on the heat transfer process has also been demonstrated using the meshless local Petrov–Galerkin (MLPG) approach. Design/methodology/approach It is true that MLPG method is time-consuming and expensive in terms of man-hours, as it is in the developing stage, but with the advent of computationally fast new-generation computers, there is a big possibility of the development of MLPG software, which will not only reduce the computational time and cost but also enhance the accuracy and precision in the results. Bi values of 0.01 and 0.10 have been taken for the experimental investigation of one-dimensional and two-dimensional rectangular fin models. The numerical simulation results obtained by the analytical method, benchmark numerical method and the MLPG method for both the models have been compared with that of the experimental investigation results for validation and found to be in good agreement. Performance of the fin has also been demonstrated. Findings The experimental and numerical investigations have been conducted for one-dimensional and two-dimensional linear and nonlinear fin models of rectangular shape. MLPG is used as a potential numerical method. Effect of radiation is also, implemented successfully. Results are found to be in good agreement with analytical solution, when one-dimensional steady problem is solved; however, two-dimensional results obtained by the MLPG method are compared with that of the finite element method and found that the proposed method is as accurate as the established method. It is also found that for higher Bi, the one-dimensional model is not appropriate, as it does not demonstrate the appreciated error; hence, a two-dimensional model is required to predict the performance of a fin. Radiative fin illustrates more heat transfer than the pure convective fin. The performance parameters show that as the Bi increases, the performance of fin decreases because of high thermal resistance. Research limitations/implications Though, best of the efforts have been put to showcase the behaviour of one-dimensional and two-dimensional fins under nonlinear conditions, at different Bi values, yet lot more is to be demonstrated. Nonlinearity, in the present paper, is exhibited by using the thermal and material properties as the function of temperature, but can be further demonstrated with their dependency on the area. Additionally, this paper can be made more elaborative by extending the research for transient problems, with different fin profiles. Natural convection model is adopted in the present study but it can also be studied by using forced convection model. Practical implications Fins are the most commonly used medium to enhance heat transfer from a hot primary surface. Heat transfer in its natural condition is nonlinear and hence been demonstrated. The outcome is practically viable, as it is applicable at large to the broad areas like automobile, aerospace and electronic and electrical devices. Originality/value As per the literature survey, lot of work has been done on fins using different numerical methods; but to the best of authors’ knowledge, this study is first in the area of nonlinear heat transfer of fins using dimensionless Bi by the truly meshfree MLPG method.

Quasi-One-Dimensional Modeling and Analysis of RBCC Dual-Mode Scramjet Engine

2019 ◽  
Vol 36 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Feng Cheng ◽  
Shuo Tang ◽  
Dong Zhang ◽  
Yi Li
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Specific Heat ◽  
Transonic Flow ◽  
Wall Heat Transfer ◽  
Dimensional Model ◽  
Dual Mode ◽  
One Dimensional ◽  
Scramjet Engine ◽  
Cfd Numerical Simulation

Abstract The quasi-one-dimensional method for the dual-mode scramjet (DMR) of the hypersonic RBCC powered vehicle was simplified in most of open researches. Furthermore, these simplified method can not fully capture the processes of wall heat transfer, changes in the boundary layer and the ratio of specific heat and the transonic flow in the reacting flow. Addressing this problem, we establish the models for processing core flow area, transonic flow and pre-combustion shock train (PCST) based on the governing equations for quasi-one-dimensional flow and certain assumptions. Thus the quasi-one-dimensional model of dual-mode scramjet engine that incorporates the changes in wall heat transfer and in the ratio of specific heat is built. Then, the reliability and accuracy of the model are assessed qualitatively and quantitatively by experiment and CFD numerical simulation. There is a high agreement between the theoretical calculations and the results of experimental data and CFD numerical simulation. This work expands the application scope and increases the reliability of quasi-one-dimensional model of dual-mode scramjet engine in RBCC engine. The results shed new light on the preliminary performance assessment and engineering application of dual-mode scramjet engine.

Design of Grid Multiscroll Chaotic Attractors via Transformations

2015 ◽  
Vol 25 (10) ◽  
pp. 1530027 ◽  
Author(s):  
Xingxing Ai ◽  
Kehui Sun ◽  
Shaobo He ◽  
Huihai Wang
Keyword(s):  
Numerical Simulation ◽  
Lyapunov Exponent ◽  
Theoretical Analysis ◽  
Experimental Verification ◽  
Equilibrium Points ◽  
Experimental Results ◽  
Chaotic Attractors ◽  
Largest Lyapunov Exponent ◽  
One Dimensional ◽  
Circular Grid

Three transformation approaches for generating grid multiscroll chaotic attractors are presented through theoretical analysis and numerical simulation. Three kinds of grid multiscroll chaotic attractors are generated based on one-dimensional multiscroll Chua system. The dynamics of the multiscroll chaotic attractors are analyzed by means of equilibrium points, eigenvalues, the largest Lyapunov exponent and complexity. As the experimental verification, we implemented the circular grid multiscroll attractor on DSP platform. The simulation and experimental results are consistent well with that of theoretical analysis, and it shows that the design approaches are effective.

scholarly journals Analysis of the applicability of the one-dimensional model for calculating thermal and thermoelectric processes in anisotropic bismuth thermoelements

2021 ◽  
Vol 2103 (1) ◽  
pp. 012215
Author(s):  
P A Popov
Keyword(s):  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Heat Flux ◽  
Thermoelectric Power ◽  
Thermal Action ◽  
Dimensional Model ◽  
Conductivity Anisotropy ◽  
Experimental Conditions ◽  
One Dimensional ◽  
The One

Abstract The results of the temperature and electric potential numerical simulation in the model of an anisotropic thermoelement under thermal action typical for the experimental conditions on shock tubes are presented. The influence of the thermal conductivity anisotropy on the temperature distribution and the generated thermoelectric power is analysed. The results of solving the inverse problem - determining the heat flux from the calculated thermoelectric power are presented. The errors in calculating the heat flux on the basis of the one-dimensional model have been determined.

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