共查询到7条相似文献,搜索用时 0 毫秒
1.
Cao Shuxiao 《保鲜与加工》1990,(4)
Two-dimensional incompressible laminar boundary layer equation can be changed into Blasius equation by means of similarity transformation. In this paper, Blasius equation 2f" '+ff"=0 is transferred into a nonlinear and autonomous system of second order by variable transforming. Taking the advantage of its approximation to linear system, the stability near zero solution can be discussed. 相似文献
2.
3.
Jin Chaosong 《保鲜与加工》1990,(3)
This paper presents a new numerical solution for Neumann problem of Helmholtz equation in R~3. The expression of the solution for this problem is obtained by use of a double layer potential and it leads to a Fredholm boundary integral equation of the first kind. Then, the existence and unicity of the integral equation which is equivalent to the boundary value problem are obtained in a suitable Sobolev space. Finally, a variational form which is equivalent to the integral equation is applied to the construction of a finite element method and the error estimate is given. 相似文献
4.
Lin Chengxian 《保鲜与加工》1989,(4):81-85
In order to compute the incompressible plane cascade flowfield in turbomachines with nothing but the Boundary Element Method, thispaper presents a numerical method by which both the velocity potentials andthe tangential velocities along the surfaces of cascade profile are computed by the Boundary Element Method, and because of this method, good results are obtained. 相似文献
5.
Jin Chaosong 《保鲜与加工》1990,(4)
This paper presents boundary element methods for the solution of elliptic partial differential equation with Neumann boundary problem in R~2. Total details of error analysis are given for general condition, and optimal estimates are obtained. For simplicity Laplace's equation is discussed in illustration. 相似文献
6.
The transient flow fields of gallgladder bile in vivo are calculated by finite element methods. Computer tomograph, ultrasound B and contrast radiography are applied to determine the moving boundary conditions, The penalty formulation and moving triangle elements have been successfully adopted and be flow fields for axisymmetric Newtonian bile flow have been obtained. The results show that there exists obvions reverse flow at the cross section (Perpendicular to Center axis) and thus forms axisymmetric vartexes inside a contracting gallbladder in vivo,Which well agree with the previous prediction. 相似文献
7.
Chen Wanming Zhou Jiaqi 《保鲜与加工》1992,(3):37-42
An A. C. load flow analysis of the reliability evaluation of composite generation and transmission systems is presented on the basis of a fast outage simulation algorithm and an optimal model of active and reactive power adjustment after outage contingencies. The information of the first -level outage events is utilized for simulating higher -level outage events in the fast outage simulation algorithm ; the optimal model is satisfactory in speed and accuracy with the application of concentric relaxation and linear increment constraint on the comprehensive adjustment of active and reactive power. As an example. the IEEE Reliability Test System is tested and the results show that the method is accurate and well-matched in speed with the method studied by R. Bllinton, et al. 相似文献