Discussion of the First Law of Thermodynamics Based on the Reynolds Transport Theorem

Los conceptos de masa, movimiento y energía han ocupado la atención de filósofos y científicos desde tiempos ancestrales. Aun cuando hubo muchos que creían que la masa y la energía se conservaban, debieron pasar muchos años hasta que la primera ley de la termodinámica adquiriera su forma actual. La ley de conservación de la energía es uno de los principios fundamentales del mundo físico como lo entendemos hoy. Negar la posibilidad del movimiento perpetuo le coloca un límite superior a la utilización de la energía y a la eficiencia termodinámica de un proceso.

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Application of the First Law of Thermodynamics to Piston Engines

Russian Engineering Research ◽

10.3103/s1068798x20070114 ◽

2020 ◽

Vol 40 (7) ◽

pp. 527-530

Author(s):

A. F. Dorokhov ◽

P. A. Dorokhov

Keyword(s):

First Law Of Thermodynamics

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Approximate Closed-Form Solutions for the Shift Mechanics of Rubber Belt Variators

Volume 6: ASME Power Transmission and Gearing Conference; 3rd International Conference on Micro- and Nanosystems; 11th International Conference on Advanced Vehicle and Tire Technologies ◽

10.1115/detc2009-86638 ◽

2009 ◽

Cited By ~ 1

Author(s):

Marco Cammalleri ◽

Francesco Sorge

Keyword(s):

Closed Form ◽

Mass Conservation ◽

Experimental Tests ◽

Speed Ratio ◽

Equilibrium Equations ◽

Closed Form Solutions ◽

Rubber Belt ◽

Linear Differential ◽

The Mathematical Model ◽

Transport Theorem

The mechanical behavior of V-belt variators during the speed ratio shift is different from the steady operation as a gross radial motion of the belt is superimposed to the circumferential motion. The theoretical analysis involves equilibrium equations similar to the steady case, but requires a re-formulation of the mass conservation condition making use of the Reynolds transport theorem. The mathematical model of the belt-pulley coupling implies the repeated numerical solution of a strongly non-linear differential system. Nevertheless, an attentive observation of the numerical diagrams suggests simple and useful closed-form approximations for the four possible working modes of any pulley, opening/closing, driver/driven, whose validity ranges over most practical cases. The present analysis focuses on the development of such simplified solutions, succeeding in an excellent matching with the numerical plots, and on the comparison of the theory with some experimental tests on a motorcycle variator, revealing a very good agreement.

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Dynamic Characteristic Analysis of New Pneumatic Bending Joint

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.271-272.1742 ◽

2012 ◽

Vol 271-272 ◽

pp. 1742-1749

Author(s):

Peng Cheng Huang ◽

Qing Hua Yang ◽

Guan Jun Bao ◽

Li Bin Zhang

Keyword(s):

Response Time ◽

Dynamic Characteristic ◽

Simulation Analysis ◽

Characteristic Analysis ◽

Pneumatic Actuators ◽

Bending Performance ◽

First Law Of Thermodynamics ◽

Existing Problems ◽

Joint Damping ◽

New Type

Aimed at existing problems on the bending performance of pneumatic bending joint, a new type of pneumatic bending joint is proposed in this paper. Double flexible pneumatic actuators are used as actuating drivers. Based on the first law of thermodynamics and the joint dynamic equation, the angle dynamic model is established and analyzed. Moreover simplified model is proposed. Meanwhile, its dynamic characteristic is analyzed through simulation analysis. The simulation suggests the following results: in the gas-filled phase, the joint’s pressure response time is about 10ms; while it is about 60ms in the gas-escape phase; and the angle response time of joint is 10 to 20ms. When the joint damping coefficient is increasing, this value will also increase.

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Reynolds transport theorem for a two-phase flow

Applied Physics Letters ◽

10.1063/1.2430675 ◽

2007 ◽

Vol 90 (2) ◽

pp. 024101 ◽

Cited By ~ 3

Author(s):

Francisco J. Collado

Keyword(s):

Two Phase Flow ◽

Phase Flow ◽

Two Phase ◽

Transport Theorem

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The Estimation of Thermal Conductivity for Alumina-Epoxy Composite Material with High Filling Volume Fraction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.918.21 ◽

2014 ◽

Vol 918 ◽

pp. 21-26

Author(s):

Chen Kang Huang ◽

Yun Ching Leong

Keyword(s):

Thermal Conductivity ◽

Composite Material ◽

Composite Materials ◽

Physical Model ◽

Electron Scattering ◽

Volume Fraction ◽

Epoxy Composite ◽

The Matrix ◽

Transport Theorem ◽

Good Agreement

In this study, the transport theorem of phonons and electrons is utilized to create a model to predict the thermal conductivity of composite materials. By observing or assuming the dopant displacement in the matrix, a physical model between dopant and matrix can be built, and the composite material can be divided into several regions. In each region, the phonon or electron scattering caused by boundaries, impurities, or U-processes was taken into account to calculate the thermal conductivity. The model is then used to predict the composite thermal conductivity for several composite materials. It shows a pretty good agreement with previous studies in literatures. Based on the model, some discussions about dopant size and volume fraction are also made.

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