Papers by Keyword: Potential Function

Abstract: Paper is devoted to development of the potential barrier model allowing to take into account the interaction between elastic reflection of particles and plasmatron walls. The coaxial magneto-plasma accelerator which has been put into practice is considered.Plasma clot change of speed and weight depending on the coordinate determined by both power characteristics and gas dynamic regularities of hypersonic jet currents in the cylindrical channel was investigated in the accelerator. Potential function and force field type modeling spatial restriction of plasma particles scattering is presented. Dynamics ofcharged particles distribution in electromagnetic field andthe plot of energy balance taking into account the erosion of channel walls have been presented. The developed model of the coaxial magneto-plasma accelerator taking into account an erosion caused by particles distribution on a low-frequency helixhas been shown.Low-frequency helixpath motion is presented as superposition of longitudinal and transverse motions. Differential equations were solved using the fourth-order Runge-Kutta fixed-step method.

Abstract: A new and effective analytical perturbation method is presented for the multipole acoustic logging in a transversely isotropic medium (TIM) whose symmetric principal axis is parallel to the borehole axis although the exact solutions could be found. In this paper, the new perturbation method is adopted to simulate the dispersion characteristic in a borehole surrounded by a TIM for the first time. The TIM is regarded as a reference unperturbed isotropic state added to the perturbations, and three perturbation quantities about moduli deviated from the isotropic medium are introduced. By selecting a group of displacement potentials and a cylindrical coordinate system oriented along the borehole axis, the zero-, first-order and second-order perturbation solutions of the multipole acoustic field are derived for the weak transversely isotropic elastic solid which has its symmetric principal axis parallel to the borehole axis. It is found that the dispersion characteristic by the perturbation method inside the borehole excited by monopole, dipole sources and quadrupole source are similar to obtained by the exact solution.

Abstract: The optimal calculaion of non-probabilistic structure reliability index is researched, where the minimum distance from the origin to the limit-state surface in the standard normal space is required. From the viewpoints of the global nolinear and local linear, it build the global approximate variational inequality. The primal coupled potential function is used to decide direction and step of searching. It is more effective in convergence and polynomials than the other methods in the related references. After a brief review, the method are compared through two numerical examples. It shows that the present method is effective and feasibility.

Abstract: Wing of an aircraft is lift producing component. It makes aircraft airborne by generating lift>weight. The wing must take the full aircraft weight during flying. So, it is very sophisticated task for designing a wing by keeping consideration of every design parameters simultaneously. This paper contains analysis of structural properties of wing by using finite element method. For well-organized design all the variables must be considered from the beginning of the design phase. The design phases for aircraft are: conceptual, preliminary and detail design. Until the preliminary design phase the aircraft structure is not considered. During these phases the material of the wing should be selected in such a way so that it can perform efficiently with less unexpected phenomena (drag) for which responsible properties are displacement, stress etc. Currently the most focusing area for the aero-elastic investigation is to design wing with good aerodynamic shape which will associated with less dragging structural behavior. It helps to reduce SFC (Specific Fuel Consumption) and so the cost. The analysis on that has done through Computational means as well as simulation technique to develop knowledge about the variation of aircraft wing structural properties.

Abstract: Using the definitions of potential functions and ordinal potential functions of strategic form games, we characterize two classes of potential games and give the solving method of the equilibria of finite potential games by testing and verifying potential games. The main contribution is proving that public goods games and social coordination games based on location strategic interaction with an exogenous network are potential games, and giving the equilibria by the method of solving potential games and ordinal potential games.

Abstract: Molecular dynamics simulation Refers to multi-body system consisting of atomicnucleusand electrons, solving Newton's equations of motion. Each nucleus is seen as a movement under the combined action of all other nucleus and electrons. By analyzing the force of every particle in the system, classical or quantum mechanical method is used to solve the position and velocity of individual particles in the system for a certain time, and to determine the state of motion of the particle, then to calculate the structure and properties of the system [1]. This paper describes the basic concepts and methods of molecular dynamics which are comprised of inter-atomic potential function like pair potential and multi-body potentials, time integration algorithm and so and.

Abstract: Nonconvex nonsmooth potential functions have superior restoration performance for the images with neat boundaries. But the nondifferentiality could cause many numerical difficulties. Thus the graduated nonconvex (GNC) method is suggested to deal with these problems. In this paper, a class of nonconvex nonsmooth approximate potential functions have been constructed, which can help our get a better initial value of the original problem. The numerical results show the restored perfprmance of the proposed methods.

Abstract: Based on the plane strain model, a three-dimensional vibration model was setup for soil dynamic response of soil surrounding large diameter pile. An accurate analytical solution was got by considering the couple effect of vertical and horizontal displacement of soil. Through the discussion parameters slenderness ratio (L/d), hysteretic damping ratio (D_s,D_v) and soil Poisson's ratio (ν),it is concluded that they are very important for the vertical vibration propproperties of soil impedance.

Abstract: When we research on pneumatic performance of aero-engine blades,some functions are not solved directly in physical domain because blade coordinates are unknown,but they can be solved after being transformed to computational domain.For potential function and stream function have the orthogonality themselves,mesh of computational domain is orthogonal after orthogonal transformation and the functions are solved easily.The existence conditions are two-dimensional flow continuity equations.If fluid is irrotational and powerful flow,potential function and stream function are both usesd to describe flow field’s velocity,pressure distribution.etc.Therefore,we select potential function and stream function as basic method for researching optimization design of aero-engine blades.

Abstract: Potential energy scan for U2 was performed by density functional theory (DFT) method at the B3LYP level in combination with the (ECP80MWB_AVQZ + 2f) basis set. The dissociation energy of U2, after being corrected for the zero-point vibrational energy, is 2.482 eV, which is in good agreement with the experiment. The calculated energy was fit to the typical potential functions of Morse, Lennard-Jones (L-J) and Rydberg. Both the Morse and Rydberg functions are good representatives of the potentials, but the Lennard-Jones function is not. The anharmonicity constant is very small. The anharmonic frequency is 113.99 cm^–1. Thermodynamic properties of entropy and heat capacity at 298.2 K – 1500 K were calculated by using DFT-B3LYP computational results and Morse parameters, respectively. The relationship between entropy and temperature was established.