Wong Sen, Yuen Manwai
Department of Mathematics and Information Technology, The Hong Kong Institute of Education, 10 Lo Ping Road, Tai Po, New Territories, Hong Kong.
ScientificWorldJournal. 2014;2014:580871. doi: 10.1155/2014/580871. Epub 2014 Mar 30.
We study, in the radial symmetric case, the finite time life span of the compressible Euler or Euler-Poisson equations in R (N) . For time t ≥ 0, we can define a functional H(t) associated with the solution of the equations and some testing function f. When the pressure function P of the governing equations is of the form P = Kρ (γ) , where ρ is the density function, K is a constant, and γ > 1, we can show that the nontrivial C (1) solutions with nonslip boundary condition will blow up in finite time if H(0) satisfies some initial functional conditions defined by the integrals of f. Examples of the testing functions include r (N-1)ln(r + 1), r (N-1) e (r) , r (N-1)(r (3) - 3r (2) + 3r + ε), r (N-1)sin((π/2)(r/R)), and r (N-1)sinh r. The corresponding blowup result for the 1-dimensional nonradial symmetric case is also given.
我们在径向对称情形下,研究(\mathbb{R}^N)中可压缩欧拉方程或欧拉 - 泊松方程的有限时间寿命。对于(t\geq0),我们可以定义一个与方程的解以及某个测试函数(f)相关的泛函(H(t))。当控制方程的压力函数(P)具有(P = K\rho^{\gamma})的形式,其中(\rho)是密度函数,(K)是常数,且(\gamma>1)时,我们可以证明,如果(H(0))满足由(f)的积分定义的某些初始泛函条件,那么具有无滑移边界条件的非平凡(C^1)解将在有限时间内爆破。测试函数的例子包括(r^{N - 1}\ln(r + 1))、(r^{N - 1}e^r)、(r^{N - 1}(r^3 - 3r^2 + 3r + \varepsilon))、(r^{N - 1}\sin((\pi/2)(r/R)))以及(r^{N - 1}\sinh r)。还给出了一维非径向对称情形下相应的爆破结果。