<p>We consider the axisymmetric Navier-Stokes equations in a finite cylinder <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\Omega \subset \mathbb {R}^3\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Ω</mi> <mo>⊂</mo> <msup> <mrow> <mi mathvariant="double-struck">R</mi> </mrow> <mn>3</mn> </msup> </mrow> </math></EquationSource> </InlineEquation>. We assume that <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(v_r\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>v</mi> <mi>r</mi> </msub> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(v_\varphi \)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>v</mi> <mi>φ</mi> </msub> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\omega _\varphi \)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ω</mi> <mi>φ</mi> </msub> </math></EquationSource> </InlineEquation> vanish on the lateral part of boundary <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\partial \Omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>∂</mi> <mi mathvariant="normal">Ω</mi> </mrow> </math></EquationSource> </InlineEquation> of the cylinder, and that <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(v_z\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>v</mi> <mi>z</mi> </msub> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq9"> <EquationSource Format="TEX">\(\omega _\varphi \)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ω</mi> <mi>φ</mi> </msub> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq10"> <EquationSource Format="TEX">\(\partial _zv_\varphi \)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>∂</mi> <mi>z</mi> </msub> <msub> <mi>v</mi> <mi>φ</mi> </msub> </mrow> </math></EquationSource> </InlineEquation> vanish on the top and bottom parts of the boundary <InlineEquation ID="IEq11"> <EquationSource Format="TEX">\(\partial \Omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>∂</mi> <mi mathvariant="normal">Ω</mi> </mrow> </math></EquationSource> </InlineEquation>, where we used standard cylindrical coordinates, and we denoted by <InlineEquation ID="IEq12"> <EquationSource Format="TEX">\(\omega =\operatorname {curl}v\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>ω</mi> <mo>=</mo> <mo>curl</mo> <mi>v</mi> </mrow> </math></EquationSource> </InlineEquation> the vorticity field. We use <InlineEquation ID="IEq13"> <EquationSource Format="TEX">\(H^3\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>H</mi> <mn>3</mn> </msup> </math></EquationSource> </InlineEquation> Sobolev estimates for the modified stream function (stream function divided by radius) and energy type estimates for gradient of swirl to derive two order reduction estimates. Finally, using the estimate <Equation ID="Equ154"> <EquationSource Format="TEX">\( \Vert v_\varphi \Vert _{L_q(0,T;L_p(\Omega ))} \le A, \)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mrow> <mo stretchy="false">‖</mo> </mrow> <msub> <mi>v</mi> <mi>φ</mi> </msub> <msub> <mrow> <mo stretchy="false">‖</mo> </mrow> <mrow> <msub> <mi>L</mi> <mi>q</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mn>0</mn> <mo>,</mo> <mi>T</mi> <mo>;</mo> <msub> <mi>L</mi> <mi>p</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mi mathvariant="normal">Ω</mi> <mo stretchy="false">)</mo> </mrow> <mo stretchy="false">)</mo> </mrow> </mrow> </msub> <mo>≤</mo> <mi>A</mi> <mo>,</mo> </mrow> </math></EquationSource> </Equation>where <i>A</i> is a given number and <InlineEquation ID="IEq14"> <EquationSource Format="TEX">\(\frac{3}{p} + \frac{2}{q} &lt; 1\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mfrac> <mn>3</mn> <mi>p</mi> </mfrac> <mo>+</mo> <mfrac> <mn>2</mn> <mi>q</mi> </mfrac> <mo>&lt;</mo> <mn>1</mn> </mrow> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq15"> <EquationSource Format="TEX">\(q&lt;\infty \)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>q</mi> <mo>&lt;</mo> <mi>∞</mi> </mrow> </math></EquationSource> </InlineEquation> we prove the existence of global regular axially-symmetric solutions.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

A Regularity Criterion for the Angular Component of Velocity in the norm \(L_q(0,T;L_p(\Omega )),\;\frac{3}{p} +\frac{2}{q}<1,\;q< \infty \), in Axisymmetric Navier-Stokes Equations in a Cylinder

  • Wiesław J. Grygierzec,
  • Wojciech M. Zaja̧czkowski

摘要

We consider the axisymmetric Navier-Stokes equations in a finite cylinder \(\Omega \subset \mathbb {R}^3\) Ω R 3 . We assume that \(v_r\) v r , \(v_\varphi \) v φ , \(\omega _\varphi \) ω φ vanish on the lateral part of boundary \(\partial \Omega \) Ω of the cylinder, and that \(v_z\) v z , \(\omega _\varphi \) ω φ , \(\partial _zv_\varphi \) z v φ vanish on the top and bottom parts of the boundary \(\partial \Omega \) Ω , where we used standard cylindrical coordinates, and we denoted by \(\omega =\operatorname {curl}v\) ω = curl v the vorticity field. We use \(H^3\) H 3 Sobolev estimates for the modified stream function (stream function divided by radius) and energy type estimates for gradient of swirl to derive two order reduction estimates. Finally, using the estimate \( \Vert v_\varphi \Vert _{L_q(0,T;L_p(\Omega ))} \le A, \) v φ L q ( 0 , T ; L p ( Ω ) ) A , where A is a given number and \(\frac{3}{p} + \frac{2}{q} < 1\) 3 p + 2 q < 1 , \(q<\infty \) q < we prove the existence of global regular axially-symmetric solutions.