scholarly journals The phenomenon of relay race molecular transfer of the amount of motion and its relationship with the diffusion phenomenon

2021 ◽  
Vol 2100 (1) ◽  
pp. 012024
Author(s):  
B M Burakhanov
Keyword(s):  
Equilibrium State ◽  
Physical Phenomenon ◽  
Race Model ◽  
Ideal Gas ◽  
Total Density ◽  
Ideal Gases ◽  
Molecular Transfer ◽  
Temperature And Pressure ◽  
Diffusion Flows ◽  
Relay Race

Abstract The very fact of molecular transfer of the amount of motion, including in an ideal gas in an equilibrium state, has long been well known. However, this fact is still not realized as a physical phenomenon of transfer, equivalent to such transfer phenomena as diffusion, thermal conductivity and viscosity. The key concept used in this paper when describing the phenomenon of relay race molecular transfer of the amount of motion is the concept - “molecular relay race type of motion”. A molecular relay race model of an ideal gas in an equilibrium state is proposed, as well as a molecular relay race model of a mixture of two ideal gases at constant temperature and pressure. It is shown that the value of the velocity modulus of diffusion flows is one of the physical characteristics of the mixture as a whole. It is also shown that the total density of the substance carried by the diffusion flows is many orders of magnitude less than the total density of the inhomogeneous multicomponent mixture.

scholarly journals Pressure effect of the mechanical, electronics and thermodynamic properties of Mg–B compounds A first-principles investigations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
GuoWei Zhang ◽  
Chao Xu ◽  
MingJie Wang ◽  
Ying Dong ◽  
FengEr Sun ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Boron Content ◽  
Structural Parameters ◽  
Debye Model ◽  
Total Density ◽  
First Principle ◽  
Volume Deformation ◽  
Temperature And Pressure ◽  
Total Density Of States

AbstractFirst principle calculations were performed to investigate the structural, mechanical, electronic properties, and thermodynamic properties of three binary Mg–B compounds under pressure, by using the first principle method. The results implied that the structural parameters and the mechanical properties of the Mg–B compounds without pressure are well matched with the obtainable theoretically simulated values and experimental data. The obtained pressure–volume and energy–volume revealed that the three Mg–B compounds were mechanically stable, and the volume variation decreases with an increase in the boron content. The shear and volume deformation resistance indicated that the elastic constant Cij and bulk modulus B increased when the pressure increased up to 40 GPa, and that MgB7 had the strongest capacity to resist shear and volume deformation at zero pressure, which indicated the highest hardness. Meanwhile, MgB4 exhibited a ductility transformation behaviour at 30 GPa, and MgB2 and MgB7 displayed a brittle nature under all the considered pressure conditions. The anisotropy of the three Mg–B compounds under pressure were arranged as follows: MgB4 > MgB2 > MgB7. Moreover, the total density of states varied slightly and decreased with an increase in the pressure. The Debye temperature ΘD of the Mg–B compounds gradually increased with an increase in the pressure and the boron content. The temperature and pressure dependence of the heat capacity and the thermal expansion coefficient α were both obtained on the basis of Debye model under increased pressure from 0 to 40 GPa and increased temperatures. This paper brings a convenient understanding of the magnesium–boron alloys.

scholarly journals Equation of state in form which relates mol fraction and molarity of two (or more) component thermodynamic system consisted of ideal gases, and it’s applications

2010 ◽  
Vol 14 (3) ◽  
pp. 859-863
Author(s):  
Marko Popovic
Keyword(s):  
Equation Of State ◽  
Special Relativity ◽  
Mole Fraction ◽  
Relativistic Effects ◽  
Thermodynamic System ◽  
Ideal Gases ◽  
Other Substances ◽  
Temperature And Pressure ◽  
Insight Into

Most people would face a problem if there is a need to calculate the mole fraction of a substance A in a gaseous solution (a thermodynamic system containing two or more ideal gases) knowing its molarity at a given temperature and pressure. For most it would take a lot of time and calculations to find the answer, especially because the quantities of other substances in the system aren?t given. An even greater problem arises when we try to understand how special relativity affects gaseous systems, especially solutions and systems in equilibrium. In this paper formulas are suggested that greatly shorten the process of conversion from molarity to mole fraction and give us a better insight into the relativistic effects on a gaseous system.

scholarly journals Towards Thermodynamics with Generalized Uncertainty Principle

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed Farag Ali ◽  
Mohamed Moussa
Keyword(s):  
Quantum Gravity ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
Ideal Gas ◽  
Considerable Change ◽  
Heisenberg Uncertainty Principle ◽  
Ideal Gases ◽  
Quantum Gravity Effect ◽  
Photon Gas ◽  
Heisenberg Uncertainty

Various frameworks of quantum gravity predict a modification in the Heisenberg uncertainty principle to a so-called generalized uncertainty principle (GUP). Introducing quantum gravity effect makes a considerable change in the density of states inside the volume of the phase space which changes the statistical and thermodynamical properties of any physical system. In this paper we investigate the modification in thermodynamic properties of ideal gases and photon gas. The partition function is calculated and using it we calculated a considerable growth in the thermodynamical functions for these considered systems. The growth may happen due to an additional repulsive force between constitutes of gases which may be due to the existence of GUP, hence predicting a considerable increase in the entropy of the system. Besides, by applying GUP on an ideal gas in a trapped potential, it is found that GUP assumes a minimum measurable value of thermal wavelength of particles which agrees with discrete nature of the space that has been derived in previous studies from the GUP.

Simulation and Modeling of Compression Stroke in Diesel Engines

2016 ◽  
Vol 823 ◽  
pp. 309-314
Author(s):  
Mahran Dawwa ◽  
Iulia Luninita Baboiu
Keyword(s):  
Diesel Engines ◽  
Simulation And Modeling ◽  
Mixture Formation ◽  
Compression Stroke ◽  
Modeling Process ◽  
Ideal Gases ◽  
Engine Combustion ◽  
Computational Fluid Dynamics Cfd ◽  
Temperature And Pressure ◽  
Thermodynamic Equations

The objective of this study is to simulate the compression stroke in diesel engines by using computational fluid dynamics (CFD), and to model the compression stroke by using thermodynamic equations for Ideal gases and polynomial function that fits thermodynamic data of JANAF tables. The most important parameters to be simulated and modeled during the compression stroke are temperature and pressure of cylinder gases because of their important effects on mixture formation inside the engine combustion chamber. The simulation part will be performed using ANSYS ICE software. The modeling part will be performed using a MATLAB program composed by the corresponding author. Simulation and modeling process will be carried out between the intake valve close (IVC) and top dead center (TDC), the results of simulation and modeling will be compared and discussed.

Ideal gas processes – and two ideal gas case studies too

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Case Studies ◽  
Constant Pressure ◽  
Ideal Gas ◽  
Heat Capacities ◽  
Carnot Cycle ◽  
State Function ◽  
Ideal Gases ◽  
First Case ◽  
The Ideal

This chapter brings together, and builds on, the results from previous chapters to provide a succinct, and comprehensive, summary of all key relationships relating to ideal gases, including the heat and work associated with isothermal, adiabatic, isochoric and isobaric changes, and the properties of an ideal gas’s heat capacities at constant volume and constant pressure. The chapter also has two ‘case studies’ which use the ideal gas equations in broader, and more real, contexts, so showing how the equations can be used to tackle, successfully, more extensive systems. The first ‘case study’ is the Carnot cycle, and so covers all the fundamentals required for the proof of the existence of entropy as a state function; the second ‘case study’ is the ‘thermodynamic pendulum’ – a system in which a piston in an enclosed cylinder oscillates to and fro like a pendulum under gravity, in both the absence, and presence, of friction.

ANISOTROPIC PRESSURE OF A QUANTUM GAS IN CONFINED SPACE

2010 ◽  
Vol 24 (26) ◽  
pp. 2669-2678
Author(s):  
HAI PANG ◽  
CHENG-WEI DONG ◽  
RONG-TAO QIU ◽  
YA-BIN ZHANG
Keyword(s):  
Ideal Gas ◽  
Boundary Effects ◽  
Anisotropic Pressure ◽  
Quantum Gas ◽  
Confined Space ◽  
Statistical Fluctuations ◽  
3D Space ◽  
Ideal Gases ◽  
Anisotropic Mechanical Properties ◽  
2D Space

In confined space, the thermodynamic potential is shape-dependent. Therefore, the pressure of ideal gases in confined space is anisotropic. We study this anisotropy in a thermodynamic manner and find that the thermodynamic pressures usually depend on the form of deformations, and hence are not equal to each other which is a natural representation of the anisotropic mechanical properties of a confined ideal gas. We also find that the boundary effects are much more significant than the statistical fluctuations under low-temperature and high-density conditions. Finally, we show that there is little difference between the boundary effects in 2D space and those in 3D space.

Property Libraries for Working Fluids for Calculating Heat Cycles, Turbines, Heat Pumps, and Refrigeration Processes

2007 ◽  
Author(s):  
H.-J. Kretzschmar ◽  
I. Stoecker ◽  
I. Jaehne ◽  
S. Herrmann ◽  
M. Kunick
Keyword(s):  
Transport Properties ◽  
Gas Turbines ◽  
High Pressures ◽  
Heat Pumps ◽  
Ideal Gas ◽  
Humid Air ◽  
Combustion Gas ◽  
Ideal Mixture ◽  
Ideal Gases ◽  
Real Fluids

The program libraries developed for calculating the thermophysical properties of working fluids can be used by engineers who routinely calculate heat cycles, steam or gas turbines, boilers, heat pumps, or other thermal or refrigeration processes. Thermodynamic properties, transport properties, derivatives, and inverse functions can be calculated. Today gas turbines are being developed for higher and higher temperatures and pressures. However, the calculation of the combustion gas as an ideal gas mixture will be inaccurate at high pressures. For this reason, a property library has been developed for humid combustion gases calculated as an ideal mixture of real fluids. The advanced adiabatic compressed air energy storage technology requires very accurate algorithms for the thermodynamic and transport properties of humid air at low temperatures and high pressures. At these parameters, humid air cannot be calculated as an ideal gas mixture. For this reason, a property library with real gas algorithms has been developed. The following properly libraries will be presented: LibHuGas for humid combustion gas mixtures at high pressures calculated as an ideal mixture of real fluids. The library also includes mixtures of steam and carbon dioxide. The dissociation at high temperatures, the poynting effect, and the condensation of water are considered as well. LibHuAir for humid air at high pressures calculated as an ideal mixture of the real fluids dry air, steam and water or ice. The dissociation at high temperatures and the poynting effect are taken into consideration. LibAmWa for mixtures of ammonia and water in the Kalina cycle and in absorption refrigeration processes. LibWaLi for mixtures of water and lithium bromide in absorption refrigeration processes. LibldGas for combustion gas mixtures calculated as an ideal mixture of ideal gases using the VDI-Guideline 4670. LibIdAir for humid air calculated as an ideal mixture of the ideal gases dry air and steam using the VDI-Guideline 4670. LibIdGasMix for 25 ideal gases and their mixtures. LibIF97 for water and steam calculated from the Industrial Formulation IAPWS-IF97 and all new backward equations of the four supplementary releases adopted by IAPWS between 2001 and 2005. LibCO2 for carbon dioxide. LibNH3 for ammonia. LibR134a for the refrigerant R134a. LibPropane for propane. LibButane_Iso and LibButane_n for Iso- and n-butane. LibHe for helium. LibH2 for hydrogen. The libraries contain the most accurate algorithms for thermodynamic and transport properties. The following software solutions will also be presented: - DLLs for Windows® applications. - Add-In FluidEXL for Excel®. - Add-On FluidLAB for MATLAB®. - Add-On FluidMAT for Mathcad®. - Properly libraries for HP, TI, and Casio pocket calculators. Student versions of all programs are available.

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