The weighted residuals method was used for obtaining the boundary integral representation of the velocity of the three-dimensional inviscid irrotational flow. It is shown that velocity in an arbitrary point of domain ...The weighted residuals method was used for obtaining the boundary integral representation of the velocity of the three-dimensional inviscid irrotational flow. It is shown that velocity in an arbitrary point of domain can be expressed through its values on the boundary. Boundary integral equations of the second kind for solving boundary-valued problems of the first and second kinds are developed. The result has been also generalised to the case of solenoidal vector fields with potential vorticity. It is shown that the resulting integral equations are Fredholm integral equations of the second kind and allow effective numerical solving of corresponding boundary-valued problems. Examples of numerical solutions for a sphere and an ellipsoid are given for demonstration of efficiency of the offered method.展开更多
Abstract： In this paper, we study the existence of a solution for fifth-order boundary value problem{u（5）（t）＋f（t,u（t）,u＂（t）=0,0〈t〈1）/u（0）=u＇（0）=u＇（1）=u＂（1）=u（4）（0）=0 Where f ∈ C（[0,1] &...Abstract： In this paper, we study the existence of a solution for fifth-order boundary value problem{u（5）（t）＋f（t,u（t）,u＂（t）=0,0〈t〈1）/u（0）=u＇（0）=u＇（1）=u＂（1）=u（4）（0）=0 Where f ∈ C（[0,1] × R2, R）. By placing certain restrictions on the nonlinear term f, we prove the existence of at least one solution to the boundary value problem with the use of the lower and upper solution method and Schauder fixed-point theorem. The construction of lower or upper solution is also present.ed. Boundary value problems of very similar type are also considered.展开更多
文摘The weighted residuals method was used for obtaining the boundary integral representation of the velocity of the three-dimensional inviscid irrotational flow. It is shown that velocity in an arbitrary point of domain can be expressed through its values on the boundary. Boundary integral equations of the second kind for solving boundary-valued problems of the first and second kinds are developed. The result has been also generalised to the case of solenoidal vector fields with potential vorticity. It is shown that the resulting integral equations are Fredholm integral equations of the second kind and allow effective numerical solving of corresponding boundary-valued problems. Examples of numerical solutions for a sphere and an ellipsoid are given for demonstration of efficiency of the offered method.
文摘Abstract： In this paper, we study the existence of a solution for fifth-order boundary value problem{u（5）（t）＋f（t,u（t）,u＂（t）=0,0〈t〈1）/u（0）=u＇（0）=u＇（1）=u＂（1）=u（4）（0）=0 Where f ∈ C（[0,1] × R2, R）. By placing certain restrictions on the nonlinear term f, we prove the existence of at least one solution to the boundary value problem with the use of the lower and upper solution method and Schauder fixed-point theorem. The construction of lower or upper solution is also present.ed. Boundary value problems of very similar type are also considered.
