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991.
Bhupendra Kumar Sharma Mamta Agarwal R.C. Chaudhary 《应用数学和力学(英文版)》2007,28(3):309-309
A theoretical analysis of three-dimensional Couette flow with radiation effect on temperature distribution has been analysed, when the injection of the fluid at the lower stationary plate is a transverse sinusoidal one and its corresponding removal by constant suction through the upper porous plate is in uniform motion. Due to this type of injection velocity, the flow becomes three-dimensional. The effect of Prandtl number, radiation parameter and injection parameter on rate of heat transfer has been examined by the help of graphs. The Prandtl number has a much greater effect on the temperature distribution than the injection or radiation parameter. 相似文献
992.
Yu. I. Sentsov 《Journal of Applied Mechanics and Technical Physics》2008,49(6):902-908
The mechanism of explosive vaporization interaction of laser radiation with matter is studied theoretically. It is shown that,
in dielectric liquids with a free surface, periodic explosive boiling is possible if the laser radiation intensity exceeds
the rate of heat transfer from the region of laser radiation absorption. Analytical expressions are obtained to estimate the
pulsating boiling period and the thickness of the surface liquid layer dispersed by fluctuation vapor bubbles during each
boiling. The degree of absorption of laser radiation by the aerosol formed above the liquid surface is estimated.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 17–24, November–December, 2008. 相似文献
993.
A numerical tool is developed for coupling natural convection in cavities with surface radiation and computations are performed for an air-filled square cavity whose four walls have the same emissivity. Compared to the adiabatic case without radiation, the top wall is cooled, the bottom wall is heated, air flow along the horizontal walls are reinforced and thermal stratification in cavity core is reduced. Detailed analysis shows that net radiative heat flux is linear with ΔT if , which is the case at low Rayleigh number, and that radiative Nusselt number is a linear function of the cavity height. Surface radiation induces an early transition to time-dependent flows: for and a cavity height of 0.335 m the critical Rayleigh number is equal to and the corresponding Hopf bifurcation is supercritical. Furthermore, multiple periodic solutions are observed between and . To cite this article: H. Wang et al., C. R. Mecanique 334 (2006). 相似文献
994.
N. A. Rubtsov S. D. Sleptsov N. A. Savvinova 《Journal of Applied Mechanics and Technical Physics》2006,47(3):377-383
Numerical modeling of the single-phase Stefan problem in a semitransparent layer with transparent, nonabsorbing, and partially
radiation-absorbing boundaries is performed. It is shown that at low temperatures of the medium, convection is a determining
factor on the boundary of the irradiated sample, and at high temperatures, radiation is predominant. The absence of absorption
on the boundaries of the layer leads to acceleration of the heating of the plate and considerable deceleration of melting
processes.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 84–91, May–June, 2006. 相似文献
995.
We investigate the bifurcation of artificial halo orbits from the Lyapunov planar family of periodic orbits around the collinear libration points of the circular, spatial, restricted three-body problem. Beside the gravitational forces, our model includes also the effect of the Solar Radiation Pressure (SRP) and this motivates the use of the term ‘artificial’ halo orbits. Indeed, as a typical problem, one may think of a solar sail, which is characterized by a performance parameter measuring the strength of the effect of the SRP on the spacecraft.To settle the model, we determine the position of the collinear points as a function of the mass and performance parameters and the energy values at which Hill׳s surfaces allow for transit orbits between the primaries. To analyze the dynamics we use a consolidated procedure which consists in the computation of a resonant normal form, allowing the reduction to the center manifold and providing an integrable approximation of the Hamiltonian dynamical system. Finally, we compute the bifurcation thresholds of the 1:1 resonant periodic orbit families (which have the standard ‘halo’ orbits as their first member) as a function of the performance and mass parameters.The results show that SRP is indeed a relevant ingredient for new dynamical features and must definitely be considered when planning a mission of a solar sail with trajectories in the neighborhoods of collinear points. 相似文献
996.
本文研究了红外探测器中红外焦平面列阵的象元———铁电薄膜微桥在红外辐射作用下的输出信号。用层合板壳作为微桥结构的力学模型,中间一层为压电材料,上下两层为金属材料电极。采用了力-电-热耦合的控制方程和变分原理,考虑了铁电薄膜的惯性力,推导出了基于Mindlin假设的压电材料层合板有限元公式。以红外探测器在夜间从飞机上探测地面的坦克为例,用有限单元法模拟了铁电薄膜微桥在红外辐射作用下的力、热、电输出信号,并对结果作了分析比较。 相似文献
997.
《Particuology》2016
Magnetic nanofluid hydrothermal analysis over a plate is studied that includes consideration of thermal radiation. The Runge–Kutta (RK4) method is utilized to get solution of ODEs which are obtained from similarity solution. In considering the impacts of Brownian motion, we applied Koo–Kleinstreuer–Li correlation to simulate the properties of CuO–water. The influence is discussed of important parameters such as the temperature index, magnetic, radiation, and velocity ratio parameters and volume fraction of nanoparticle on hydrothermal behavior. Results illustrate that the coefficient of skin friction enhances with enhancing magnetic parameter while reduces with enhancing velocity ratio parameter. Also the Nusselt number was found to directly depend on the velocity ratio and temperature index parameters but has an inverse dependence on the magnetic and radiation parameters. 相似文献
998.
999.
Acoustic wave propagation from surrounding medium into a soft material can generate acoustic radiation stress due to acoustic momentum transfer inside the medium and material, as well as at the interface between the two. To analyze acoustic-induced deformation of soft materials, we establish an acoustomechanical constitutive theory by com-bining the acoustic radiation stress theory and the nonlinear elasticity theory for soft materials. The acoustic radiation stress tensor is formulated by time averaging the momen-tum equation of particle motion, which is then introduced into the nonlinear elasticity constitutive relation to construct the acoustomechanical constitutive theory for soft materials. Considering a specified case of soft material sheet subjected to two counter-propagating acoustic waves, we demonstrate the nonlinear large deformation of the soft material and ana-lyze the interaction between acoustic waves and material deformation under the conditions of total reflection, acoustic transparency, and acoustic mismatch. 相似文献
1000.
余燊 《应用数学和力学(英文版)》1993,14(7):597-605
Further exploration of the Ω-field theory as first proposed by Yu (1989) is here presented to cover the equation of motion of a test particle which induces gravitational radiation. The same theory is shown to contain an exact gravitational radiation equation derived as a logical consequence of field equations without extra postulates. In this general dynamic context the theory is renamed "The (Ω,Aμr) field Theory". 相似文献