scholarly journals Estimation of the Maximum Temperature in a Radially Constricted Gas Discharge Between Electrodes

1961 ◽  
Vol 14 (1) ◽  
pp. 129
Author(s):  
PW Seymour
Keyword(s):  
Heat Conduction ◽  
Steady State ◽  
Free Boundary ◽  
Cross Section ◽  
Discharge Tube ◽  
Boundary Surface ◽  
Gas Discharge ◽  
Maximum Temperature ◽  
Main Question ◽  
The Cross

A steady-state deuterium discharge between two electrodes is considered and the free boundary surface of the plasma is assumed thermally insulated when pinched away from the walls of the discharge tube. Cooling is therefore by heat conduction to the electrodes, compared to which bremsstrahlung loss is shown to be negligible if the discharge is not too long. The main question examined is how much the maximum temperature T m can be raised by constricting the cross section of the discharge near the centre.

An Analytical Method of Analyzing the Heat Conduction for the Unequal Cross-Section Straight Fin

2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song
Keyword(s):  
Heat Conduction ◽  
Cross Section ◽  
Analytical Method ◽  
Thermal Analyses ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Calculation Results ◽  
The Cross ◽  
Analytical Expressions

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.

The Polytropic Approach in Modelling Compressible Flows Through Constant Cross-Section Pipes

2021 ◽  
Author(s):  
Alessandro Ferrari ◽  
Oscar Vento ◽  
Tantan Zhang
Keyword(s):  
Steady State ◽  
Cross Section ◽  
Compressible Flows ◽  
Analytical Formula ◽  
Local Maximum ◽  
Wall Friction ◽  
Numerical Code ◽  
Maximum Temperature ◽  
Constant Cross Section ◽  
Polytropic Exponent

Abstract A compressible flow with wall friction has been predicted in a constant cross-section duct by means of a barotropic modelling approach, and new analytical formulas have been proposed that also allow any possible heat transfer to the walls to be taken into account. A comparison between the distributions of the steady-state flow properties, pertaining to the new formulas, and to those of a classic Fanno analysis has been performed. In order to better understand the limits of the polytropic approach in nearly chocked flow applications, a numerical code, which adopts a variable polytropic coefficient along the duct, has been developed. The steady-state numerical distributions along the pipe, obtained for either a viscous adiabatic or an inviscid diabatic flow by means of this approach, coincide with those of the Fanno and Rayleigh models for Mach numbers up to 1. A constant polytropic exponent can be adopted for a Fanno flow that is far from choking conditions, while it cannot be adopted for the simulation of a Rayleigh flow, even when the flow is not close to choking conditions. Finally, under the assumption of diabatic flows with wall friction, the polytropic approach, with a constant polytropic exponent, is shown to be able to accurately approximate cases in which no local maximum is present for the temperature along the duct. The Mach number value at the location where the local maximum temperature possibly occurs has been obtained by means of a new analytical formula.

The Transverse Vibration of a Doubly Tapered Beam

1977 ◽  
Vol 44 (1) ◽  
pp. 123-126 ◽  
Author(s):  
D. O. Banks ◽  
G. J. Kurowski
Keyword(s):  
Free Boundary ◽  
Boundary Conditions ◽  
Cross Section ◽  
Transverse Vibration ◽  
Eigenvalues And Eigenfunctions ◽  
Free Boundary Conditions ◽  
Tapered Beam ◽  
Transverse Vibrations ◽  
The Cross ◽  
Homogeneous Beam

We analyze the transverse vibrations of a thin homogeneous beam which is symmetric with respect to the x-y and x-z planes. The cross section of the beam at x is assumed to have the form D(x)={(x,y,z)|x∈[0,1],y=xαy1,z=xβz1,(y1,z1)∈D1} where D1 is the cross section at x = 1. Expressions are obtained from which the eigenvalues and eigenfunctions can be easily found for 0 ≤ α < 2 and all combinations of clamped, hinged, guided, and free boundary conditions at both ends of the beam.

scholarly journals The Influence of Thermoelectric Effects on the Maximum Temperature in a Radially Constricted Gas Discharge Between Electrodes

1961 ◽  
Vol 14 (2) ◽  
pp. 279
Author(s):  
PW Seymour
Keyword(s):  
Steady State ◽  
Heat Loss ◽  
Gas Discharge ◽  
Maximum Temperature ◽  
Thermoelectric Effects

In an earlier paper the author provided a method for estimating the maximum temperature in a steady-state, centrally constricted, highly ionized deuterium discharge between electrodes. The analysis applied to discharges not too long, so that bremsstrahlung loss could be neglected compared to the main heat loss by conduction to the electrodes, and thermoelectric effects were not included.

Identification of the Workspace Boundary Of a General 3-R Manipulator

2005 ◽  
Vol 128 (1) ◽  
pp. 236-242 ◽  
Author(s):  
Erika Ottaviano ◽  
Manfred Husty ◽  
Marco Ceccarelli
Keyword(s):  
Cross Section ◽  
Boundary Surface ◽  
Boundary Curve ◽  
Numerical Examples ◽  
Cartesian Space ◽  
Order Polynomial ◽  
The Cross ◽  
Design Characteristics ◽  
Algebraic Formulation ◽  
Workspace Boundary

In this paper an algebraic formulation is presented for the boundary workspace of 3-R manipulators in Cartesian Space. It is shown that the cross-section boundary curve can be described by a 16th order polynomial as function of radial and axial reaches. The cross-section boundary curve and workspace boundary surface are fully cyclic. Geometric singularities of the curve are identified and characterized. Numerical examples are presented to show the usefulness of the proposed investigation and to classify the design characteristics.

Study on Calculation Difference of the SCWR Core Steady-State Analysis Code

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Lianjie Wang ◽  
Lei Yao ◽  
Ping Yang ◽  
Di Lu ◽  
Wenbo Zhao
Keyword(s):  
Steady State ◽  
Cross Section ◽  
Power Distribution ◽  
Group Structure ◽  
Three Dimensional ◽  
Thermal Hydraulics ◽  
Steady State Analysis ◽  
Energy Group ◽  
The Cross ◽  
State Analysis

Abstract The three-dimensional code system supercritical water-cooled reactor (SCWR) coupled neutronics/thermal-hydraulics analysis (SNTA) code is developed for SCWR core steady-state analysis by coupling neutronics/thermal-hydraulics (N/T). This paper studies the calculation difference between the SNTA code and the standard reactor analysis code (SRAC). By using the impacts exclusive method, it is confirmed that the calculation difference between these two codes is caused by different feedback of the cross section. The cross section data and the energy group structure of the SRAC code differ from the SNTA code, and the density coefficient of reactivity calculated by the SRAC code is higher, which means the feedback of the density and power distribution is bigger and the axial power distribution varies rapidly. The SNTA code with finer energy group structure is suitable for the performance analysis of SCWR core which has strong N/T coupling characteristics.

scholarly journals Effect of Tool Rotational Speed on the Microstructure and Mechanical Properties of Bobbin Tool Friction Stir Welded 6082-T6 Aluminum Alloy

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 894 ◽  
Author(s):  
Yupeng Li ◽  
Daqian Sun ◽  
Wenbiao Gong
Keyword(s):  
Aluminum Alloy ◽  
Cross Section ◽  
Heat Affected Zone ◽  
Rotational Speed ◽  
Maximum Temperature ◽  
Friction Stir ◽  
Fracture Location ◽  
Microhardness Distribution ◽  
Average Grain Size ◽  
The Cross

Samples of 6082-T6 aluminum alloy were welded by bobbin tool friction stir welding at different rotational speeds. The thermal cycles, microstructure, microhardness, and tensile properties of the specimens were investigated. The results show that the maximum temperature at the joint increases first and then decreases with increasing rotational speed, and the maximum temperature is 509 °C at 1000 r/min. The macromorphology of the cross-section of the joint is rectangular, and an ‘’S” line and gray-white texture can be observed. The stirred zone had much smaller equiaxed recrystallized grains. With increasing welding speed, the average grain size in the stirred zone region decreases. The microhardness distribution of the cross-section of all joints is W-shaped. When the rotational speed increases, the hardness of the heat-affected zone decreases gradually, and the hardness of the stirred zone increases. At 600 r/min, the strength is the lowest. The fracture location is between the stirred zone and the thermomechanically affected zone. When the rotational speed is increased, the fracture location is entirely located in the heat affected zone, and the fracture surface is dimple-like; the strength significantly increases and reaches a maximum at 800 r/min.

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