scholarly journals Quantum Lenoir Engine with a Single Particle System in a One Dimensional Infinite Potential Well

POSITRON ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 81
Author(s):  
Yohanes Dwi Saputra
Keyword(s):  
Quantum System ◽  
Single Particle ◽  
Thermal Efficiency ◽  
Particle System ◽  
Ideal Gas ◽  
Working Fluid ◽  
Potential Well ◽  
One Dimensional ◽  
Infinite Potential Well ◽  
The Ideal

Lenoir engine based on the quantum system has been studied theoretically to increase the thermal efficiency of the ideal gas. The quantum system used is a single particle (as a working fluid instead of gas in a piston tube) in a one-dimensional infinite potential well with a wall that is free to move. The analogy of the appropriate variables between classical and quantum systems makes the three processes for the classical Lenoir engine applicable to the quantum system. The thermal efficiency of the quantum Lenoir engine is found to have the same formulation as the classical one. The higher heat capacity ratio in the quantum system increases the thermal efficiency of the quantum Lenoir engine by 56.29% over the classical version at the same compression ratio of 4.41.

The combined effect of lattice’s uniaxial strains and electron–phonon interaction’s screening on TBEC of the intersite bipolarons

2016 ◽  
Vol 30 (26) ◽  
pp. 1650186
Author(s):  
B. Yavidov ◽  
SH. Djumanov ◽  
T. Saparbaev ◽  
O. Ganiyev ◽  
S. Zholdassova ◽  
...  
Keyword(s):  
Ideal Gas ◽  
Einstein Condensation ◽  
Chain Model ◽  
One Dimensional ◽  
Electron Phonon Interaction ◽  
Model Lattice ◽  
Experimental Values ◽  
Bose Einstein ◽  
Derivatives Of ◽  
The Ideal

Having accepted a more generalized form for density-displacement type electron–phonon interaction (EPI) force we studied the simultaneous effect of uniaxial strains and EPI’s screening on the temperature of Bose–Einstein condensation [Formula: see text] of the ideal gas of intersite bipolarons. [Formula: see text] of the ideal gas of intersite bipolarons is calculated as a function of both strain and screening radius for a one-dimensional chain model of cuprates within the framework of Extended Holstein–Hubbard model. It is shown that the chain model lattice comprises the essential features of cuprates regarding of strain and screening effects on transition temperature [Formula: see text] of superconductivity. The obtained values of strain derivatives of [Formula: see text] [Formula: see text] are in qualitative agreement with the experimental values of [Formula: see text] [Formula: see text] of La[Formula: see text]Sr[Formula: see text]CuO4 under moderate screening regimes.

A Study of a Sharp 90 Degree Curved Flow

1992 ◽  
Author(s):  
R. H. Kim
Keyword(s):  
Turbulence Model ◽  
Ideal Gas ◽  
Radius Of Curvature ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Algebraic Stress Model ◽  
Finite Difference Technique ◽  
Curved Tube ◽  
Kinetic Energy Loss ◽  
The Ideal

Abstract An investigation of air flow along a 90 degree elbow-like tube is conducted to determine the velocity and temperature distributions of the flow. The tube has a sharp 90 degree turn with a radius of curvature of almost zero. The flow is assumed to be a steady two-dimensional turbulent flow satisfying the ideal gas relation. The flow will be analyzed using a finite difference technique with the K-ε turbulence model, and the algebraic stress model (ASM). The FLUENT code was used to determine the parameter distributions in the passage. There are certain conditions for which the K-ε model does not describe the fluid phenomenon properly. For these conditions, an alternative turbulence model, the ASM with or without QUICK was employed. FLUENT has these models among its features. The results are compared with the result computed by using elementary one-dimensional theory including the kinetic energy loss along the passage of the sharp 90 degree curved tube.

Quantum complexity associated with tunneling

2019 ◽  
Vol 19 (3&4) ◽  
pp. 222-236
Author(s):  
Ofir Flom ◽  
Asher Yahalom ◽  
Haggai Zilberberg ◽  
L.P. Horwitz ◽  
Jacob Levitan
Keyword(s):  
Quantum Effect ◽  
Entropy Function ◽  
Potential Well ◽  
Rapid Rise ◽  
Dimensional Model ◽  
One Dimensional ◽  
Spatial Entropy ◽  
Quantum Complexity ◽  
Entropy Growth ◽  
Infinite Potential Well

We use a one dimensional model of a square barrier embedded in an infinite potential well to demonstrate that tunneling leads to a complex behavior of the wave function and that the degree of complexity may be quantified by use of a locally defined spatial entropy function defined by S=-\int |\Psi(x,t)|^2 \ln |\Psi(x,t)|^2 dx . We show that changing the square barrier by increasing the height or width of the barrier not only decreases the tunneling but also slows down the rapid rise of the entropy function, indicating that the locally defined entropy growth is an essentially quantum effect.

scholarly journals EFFICIENCY OF THE REGENERATIVE CYCLE OF BRIGHTON WITH VARIABLE THERMOPHYSICAL PROPERTIES OF THE WORKING FLUID (Part 2)

2018 ◽  
Vol 41 (3) ◽  
pp. 5-13
Author(s):  
A.A. Khalatov ◽  
S.D. Severin ◽  
O.S. Stupak ◽  
O.V. Shihabutinova
Keyword(s):  
Moisture Content ◽  
Thermophysical Properties ◽  
Thermal Efficiency ◽  
Second Law Of Thermodynamics ◽  
Maximum Temperature ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Carnot Cycle ◽  
Regenerative Cycle ◽  
The Ideal

The data about thermodynamic efficiency of the ideal Brighton cycle with heat regeneration with constant thermophysical properties of the working fluid, as well as the Brighton cycle with heat recovery and the wetting of the working fluid at the inlet to the turbine (with variable thermophysical properties of the working fluid). The inapplicability of comparison of the thermal efficiency of the Brighton cycle with heat recovery and the wetting of the working fluid at the inlet to the turbine with the thermal efficiency of the equivalent ideal Carnot cycle is shown. The analysis of the thermodynamic efficiency of an ideal regenerative Brighton cycle with a decrease in the working body at the entrance to the turbine allows us to make the following conclusions: With the growth of the mass moisture content of the working fluid when entering the turbine, the thermal efficiency of the regenerative cycle increases, but decreases with an increase in the degree of increase in the pressure level in the cycle. High values ​​of the thermal efficiency of the cycle () can be achieved with relatively small values ​​of the degree of increase in the pressure in the cycle () and high (up to d = 0,5) values ​​of the mass moisture content of the working body when entering the turbine. It is shown that under certain conditions the thermal efficiency of the regenerative cycle with the decrease of the working body when entering the turbine may be greater than the thermal efficiency of a similar ideal Carnot cycle, which does not contradict the second law of thermodynamics, since the condition for the implementation of the Carnot cycle is the immutability of the thermophysical properties of the working body in a loop In this regard, the use of the expression for the thermal efficiency of the ideal Carnot cycle is not used as a criterion for assessing the efficiency of cycles of power plants with highly variable thermophysical properties of the working fluid. It is also shown that the thermal efficiency of the regenerative cycle with the decrease of the working body when entering the turbine is always lower than the thermal efficiency of the equivalent non-equilibrium Carnot cycle with a change in the specific heat of the working fluid, which corresponds to the second law of thermodynamics. It is shown that the Brighton regenerative cycle with a decrease in the working body before the turbine can be represented as a conditional cycle with a higher maximum temperature of the cycle, which, depending on the mass content of the moisture content of the working body, can in 1,2 ... 2,5 times exceed the actual maximum temperature cycle, which determines the high values ​​of its thermal efficiency.

Adiabatic Analysis of Rotary Displacer Stirling Engine

2018 ◽  
Author(s):  
AmirHossein Bagheri ◽  
William C. Mullins ◽  
Phillip R. Foster ◽  
Huseyin Bostanci
Keyword(s):  
Ideal Gas ◽  
Stirling Engine ◽  
Analytical Models ◽  
Working Fluid ◽  
Power Cylinder ◽  
Significant Difference ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
The Cost ◽  
The Ideal

Utilizing analytical models at the initial stages of Stirling engine (SE) development is a common approach since the cost could be excessive when experimental (i.e., building prototypes) or even numerical (i.e., using Computational Fluid Dynamics (CFD)) approaches are taken first. One of the well-known analyses in this area is the adiabatic analysis that assumes working fluid to be an ideal gas, and adiabatic expansion and compression processes in the power cylinder. Although adiabatic analysis neglects pressure loss in the cycle, it still predicts operating envelope and performance with a better accuracy compared to isothermal (Schmidt) analysis. This study considers the adiabatic analysis that was originally developed for conventional, reciprocating displacer SE configuration, and aims to adapt it for an innovative, rotary displacer SE configuration. The analysis enables to present pressure-volume diagrams, and estimates the amount of generated work and the efficiency. The results, when compared to that of the ideal Schmidt analysis, indicate up to 4.6% lower values of the generated work, suggesting a significant difference between the two ideal assumptions.

The Effect of Material Properties on the Thermal Efficiency of the Minto Solar Wheel

1980 ◽  
Vol 102 (2) ◽  
pp. 504-507 ◽  
Author(s):  
S. Lin ◽  
R. Bhardwaj
Keyword(s):  
Thermal Performance ◽  
Thermal Efficiency ◽  
Material Properties ◽  
Working Fluid ◽  
Working Fluids ◽  
Mean Diameter ◽  
The Mean ◽  
The Ideal

The characteristic of the thermal performance of the Minto solar wheel is that its thermal efficiency is strongly dependent on the material properties of the working fluid. For a specified working fluid, the thermal efficiency of the ideal cycle of the Minto solar wheel is dependent only on the mean diameter of the wheel. To study the effect of the material properties of the working fluid on the ideal thermal efficiency, 14 working fluids are selected, and their thermal efficiencies as functions of the mean diameter of the wheel are calculated and compared with each other. Among these fluids, R-12, R-115, R-500, R-22 and R-13B1 achieve better thermal performance than the others.

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