On the role of pressure in the theory of MHD equations

Autor: Minsuk Yang, Jiří Neustupa
Rok vydání: 2021
Předmět:
Zdroj: Nonlinear Analysis: Real World Applications. 60:103283
ISSN: 1468-1218
DOI: 10.1016/j.nonrwa.2020.103283
Popis: We consider the system of MHD equations in Ω × ( 0 , T ) , where Ω is a domain in R 3 and T > 0 , with the no slip boundary condition for the velocity u and the Navier-type boundary condition for the magnetic induction b . We show that an associated pressure p , as a distribution with a certain structure, can be always assigned to a weak solution ( u , b ) . The pressure is a function with some rate of integrability if the domain Ω is “smooth”, see section 3. In section 4, we study the regularity of p in a sub-domain Ω 1 × ( t 1 , t 2 ) of Ω × ( 0 , T ) , where u (or, alternatively, both u and b ) satisfies Serrin’s integrability conditions. Regularity criteria for weak solutions to the MHD equations in terms of π ≔ p + 1 2 | b | 2 are studied in section 5. Finally, section 6 contains remarks on analogous results in the case of Navier’s or Navier-type boundary conditions for the velocity u .
Databáze: OpenAIRE