Numerical simulation of flow in hydrokinetic turbine channel to improve its efficiency by using first and second-law efficiency analysis

2022 ◽  
Vol 244 ◽  
pp. 110400
Author(s):  
Mohamed El-Sawy ◽  
Ahmed S. Shehata ◽  
A.H Abdelbaky Elbatran ◽  
Adil Tawfiq
Keyword(s):  
Numerical Simulation ◽  
Efficiency Analysis ◽  
Second Law ◽  
Hydrokinetic Turbine

Utilizing the Effort/Motion Approach in the Simulation of Interconnected Rigid Body Systems

1997 ◽  
Author(s):  
N. Duke Perreira
Keyword(s):  
Numerical Simulation ◽  
Rigid Body ◽  
Multibody Systems ◽  
Invariant Form ◽  
Second Law ◽  
Orthogonal Projections ◽  
Gauge Invariant ◽  
Motion Equations ◽  
Newton's Second Law ◽  
Constraint Surface

Abstract The effort/motion approach has been developed for use in designing, simulating and controlling multibody systems. Some aspects of each of these topics are discussed here. In the effort/motion formulation two sets of equations based on the orthogonal projections of a dimensional gauge invariant form of Newton’s Second Law occur. The projections are onto the normal and tangent directions of a dimensional gauge invariant constraint surface. The paper shows how these equations are obtained for a particular linkage with redundant effort and motion actuation. Two alternative Runga-Kutta based approaches for numerical simulation of the effort/motion equations are developed and applied in simulating the motion and determining the effort generated in the example linkage under various conditions. Oscillation about equilibrium positions, solutions with constant motion and with constant effort are given as examples of the approach.

Numerical Simulation Method for Predicting Chloride Concentration Distributing around Reinforcement in Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 3138-3142
Author(s):  
Xian Li Wang ◽  
Guang Shu Ma ◽  
Chun Ling Qi
Keyword(s):  
Numerical Simulation ◽  
Service Life ◽  
Chloride Concentration ◽  
Mass Conservation ◽  
Simulation Method ◽  
Second Law ◽  
Exposed Surface ◽  
Rc Structures ◽  
Numerical Simulation Method ◽  
Section Shape

The reinforcement in concrete alters the pathway for chloride transporting and in turn causes the chloride concentration to accumulate faster near the reinforcement closest to the exposed surface. A mass conservation matrix equation under the non-stable diffusion based on the Fick’s second law was derived. Hereby, a numerical simulation method for predicting chloride concentration in concrete was established utilizing the compiled module based on FEA. The validity of the method was verified by the comparison with the analytical results. The proposed method has a wider applicability for predicting the service life of RC structures. And it can be applied flexibly to any complicated section shape of RC members with multi-boundary attacked by chloride and the reinforcement considered simultaneously.

scholarly journals Efficiency analysis of control algorithms in spatially distributed systems with chaotic behavior

2014 ◽  
Vol 24 (4) ◽  
pp. 759-770 ◽  
Author(s):  
Łukasz Korus
Keyword(s):  
Numerical Simulation ◽  
Distributed Systems ◽  
Lyapunov Method ◽  
Chaotic Behavior ◽  
Efficiency Analysis ◽  
Control Algorithms ◽  
Controlling Chaos ◽  
Qualitative And Quantitative ◽  
Spatially Distributed ◽  
Definition Of

Abstract The paper presents results of examination of control algorithms for the purpose of controlling chaos in spatially distributed systems like the coupled map lattice (CML). The mathematical definition of the CML, stability analysis as well as some basic results of numerical simulation exposing complex, spatiotemporal and chaotic behavior of the CML were already presented in another paper. The main purpose of this article is to compare the efficiency of controlling chaos by simple classical algorithms in spatially distributed systems like CMLs. This comparison is made based on qualitative and quantitative evaluation methods proposed in the previous paper such as the indirect Lyapunov method, Lyapunov exponents and the net direction phase indicator. As a summary of this paper, some conclusions which can be useful for creating a more efficient algorithm of controlling chaos in spatially distributed systems are made.

Effect of Heat Transfer on the First and Second Law Efficiency Analysis and Optimization of an Air-standard Atkinson Cycle

2018 ◽  
Vol 56 (3) ◽  
pp. 433-438
Author(s):  
A. Hajipour ◽  
M. M. Rashidi ◽  
M. E. Ali ◽  
N. Freidoonimehr ◽  
M. Fallahian
Keyword(s):  
Heat Transfer ◽  
Efficiency Analysis ◽  
Second Law ◽  
Atkinson Cycle

A Rational Efficiency Analysis of Comparisons and Trends in Gas Turbines for Cogeneration

1985 ◽  
Author(s):  
Sergio S. Stecco ◽  
Giampaolo Manfrida
Keyword(s):  
Electric Power ◽  
Heat Production ◽  
Gas Turbines ◽  
Power Index ◽  
Efficiency Analysis ◽  
Second Law ◽  
Efficiency Coefficient ◽  
Turbine Plant ◽  
Gas Turbine Plant ◽  
Regenerative Design

The performance of gas turbines in cogeneration is examined by means of a second-law approach. Different cycle parameters, for both simple and regenerative design, are investigated together with different options for process or utility heat production. A reference electric power size of 4 MW is assumed for these comparisons. Results are presented as a set of parameters (electric power index, rational efficiency, coefficient of utilization). A new parameter, named versatility index, effectively indicates the broadness of the design thermal loads which can be handled by a gas turbine plant.

scholarly journals Second law efficiency analysis of air injection into inner tube of double tube heat exchanger

2021 ◽  
Vol 60 (1) ◽  
pp. 1465-1476
Author(s):  
Nazaruddin Sinaga ◽  
Saleh khorasani ◽  
Kottakkaran Sooppy Nisar ◽  
Amr Kaood
Keyword(s):  
Heat Exchanger ◽  
Efficiency Analysis ◽  
Air Injection ◽  
Second Law ◽  
Tube Heat Exchanger
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