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21.
A. Yevtushenko R. Kultchytsky-Zhyhailo 《Archive of Applied Mechanics (Ingenieur Archiv)》1998,68(2):128-136
Summary An axisymmetric contact problem with frictional heating is considered in which a parabolic annular punch is pressed into
a plane surface and rotates about its axis of symmetry at constant speed. The problem is formulated in terms of one governing
equation with unknown pressure. This equation is solved numerically. The change of the geometry of the contact region and
pressure has been investigated.
Received 21 May 1997; accepted for publication 23 June 1997 相似文献
22.
A. Yevtushenko J. Tolstoj-Sienkiewicz 《Archive of Applied Mechanics (Ingenieur Archiv)》2006,76(1-2):33-47
The analysis of the heat distribution between a stationary pin and rotating ring was considered. To solution of the governing quasi-stationary heat conductivity equation the finite Fourier transform was used. The convective cooling from outer and internal surface of the ring as the boundary conditions were considered. The ring surface temperature, the average temperature on the ring surface and the heat distribution coefficient for the studied system were determined. The numerical results for the temperatures and heat distribution coefficient which demonstrated the effects of the Biot number and internal radius of the ring on them, were presented. 相似文献
23.
The paper investigates the effects of heat transfer in MHD flow of viscoelastic stratified fluid in porous medium on a parallel plate channel inclined at an angle θ. A laminar convection flow for incompressible conducting fluid is considered. It is assumed that the plates are kept at different temperatures which decay with time. The partial differential equations governing the flow are solved by perturbation technique. Expressions for the velocity of fluid and particle phases, temperature field, Nusselt number, skin friction and flow flux are obtained within the channel. The effects of various parameters like stratification factor, magnetic field parameter, Prandtl number on temperature field, heat transfer, skin friction, flow flux, velocity for both the fluid and particle phases are displayed through graphs and discussed numerically. 相似文献
24.
This paper presents a mathematical modelling and numerical calculations of heat conduction problems where laser generated heat is assumed as a surface heat source. Also the effect of a laser time structure on a hardened layer depth is examined. Temperature profiles for different laser pulse shapes are determined from the solution of a linear one-dimensional heat conduction equation for semi-infinite medium and discussed in terms of the parameters evolution such as dimensionless: temperature, heat flux, hardening depth, laser impulse duration and increasing time of triangular pulse shape. 相似文献
25.
S.M. Soskin R. Mannella O.M. Yevtushenko 《Communications in Nonlinear Science & Numerical Simulation》2010,15(1):16-23
We show that, in spatially periodic Hamiltonian systems driven by a time-periodic coordinate-independent (AC) force, the upper energy of the chaotic layer grows unlimitedly as the frequency of the force goes to zero. This remarkable effect is absent in any other physically significant systems. It gives rise to the divergence of the rate of the spatial chaotic transport. We also generalize this phenomenon for the presence of a weak noise and weak dissipation. We demonstrate for the latter case that the adiabatic AC force may greatly accelerate the spatial diffusion and the reset rate at a given threshold. 相似文献
26.
27.
N Venkataramani K Muralfedharan A Datta S N Bhatia OM Prakash C M Srivastava 《Pramana》1988,30(5):L455-L457
Zr and Ti have been substituted in the system Y1−x
M
x
Ba2Cu3O7−δ(M=Zr, Ti,x=0.05,0.1). We find that theT
c value is unchanged, ∼90K for Zr substitutions up to 10% and in the case of Ti substitutions theT
c drops significantly. These changes may arise from their site preference. 相似文献
28.
Influence of bath composition and deposition parameters on nanostructure and thermal stability of gold 总被引:1,自引:0,他引:1
Nanocrystalline gold is electrodeposited from a stable nontoxic bath, in which Au+ is stabilized by complex formation with 3-mercapto-1-propanesulfonic acid sodium salt. Nanoscaling is achieved by pulse techniques. The crystallite size is strongly dependent on physical and chemical process parameters, such as pulse duration, current density, bath temperature, type, and amount of additives; especially, we observe a decrease of the crystallite size down to 16 nm by the proper choice of current density and temperature, and down to 7 nm by the use of additives. The thermal stability of nanocrystalline gold is investigated by in situ high-temperature X-ray diffraction; nanogold exhibits a thermal stability up to 673 K. An activation energy of 37 kJ mol−1 is determined for the grain-growth kinetics.Paper presented at the “Jahrestagung der Fachgruppe Angewandte Electrochemie der Gesellschaft Deutscher Chemiker, Düsseldorf, 11.–14.06.2005” 相似文献
29.
This paper deals with the one-dimensional transient heat conductivity contact problem of a sliding two semi-spaces, which
induces effects of friction, heat generation and water during braking. In the present temperature analysis the capacity of
the frictional source on the contact plane dependent on the time of braking. The problem solved exactly using the Laplace
transform technique. Numerical results for the temperature are obtained for the different values of the input parameter, which
characterise the duration of the increase of the contact pressure during braking from zero to the maximum value.
An analytical formulae for the abrasive wear of the contact plane is obtained in the assumption, that the wear coefficient
is the linear function of the contact temperature.
Received on 8 September 1998 相似文献
30.
A. Yevtushenko J. Tolstoj-Sienkiewicz 《Archive of Applied Mechanics (Ingenieur Archiv)》2007,77(11):767-777
The solution of the mixed quasi-stationary heat conduction problem for the ring has been obtained by using a finite Fourier
transformation. The heating on the external side surface of the ring due to any locally distributed heat flux, as well as
the convective cooling from internal side surface and from the end faces are considered. It has been proved that for some
special geometrical and thermo-physical parameters of problem the received solution agrees with well known studies. The influence
of some distribution intensity form of heat flux on the maximum temperature was studied. 相似文献