大连大学学报
大連大學學報
대련대학학보
JOURNAL OF DALIAN UNIVERSITY
2014年
3期
34-36
,共3页
基矢量%物质导数%流体运动微分方程式%柱坐标系%球坐标系
基矢量%物質導數%流體運動微分方程式%柱坐標繫%毬坐標繫
기시량%물질도수%류체운동미분방정식%주좌표계%구좌표계
base vectors%material derivative%fluid motion differential equation%cylindrical coordinates%spherical coordinates
推导柱坐标系及球坐标系下流体运动微分方程组通常采用的方法是根据矢量形式的运动微分方程式,利用物质导数的基本公式和正交曲线坐标系各基矢量的偏导数公式来进行,推导过程相当繁琐,尤其在教学过程中,在课堂内完成上述具体推导过程几乎是不可能的。为了寻找一种简捷的推导方法,本文依据基矢量物质导数的基本公式,计算得出了柱坐标系及球坐标系下的基矢量物质导数公式,并将它们分别应用于柱坐标系及球坐标系下的流体运动微分方程组的推导过程中。结果表明:如果将柱坐标系及球坐标系下基矢量的物质导数公式作为基本公式使用,则可以使上述坐标系下流体运动微分方程组的推导过程得到很大程度的简化。
推導柱坐標繫及毬坐標繫下流體運動微分方程組通常採用的方法是根據矢量形式的運動微分方程式,利用物質導數的基本公式和正交麯線坐標繫各基矢量的偏導數公式來進行,推導過程相噹繁瑣,尤其在教學過程中,在課堂內完成上述具體推導過程幾乎是不可能的。為瞭尋找一種簡捷的推導方法,本文依據基矢量物質導數的基本公式,計算得齣瞭柱坐標繫及毬坐標繫下的基矢量物質導數公式,併將它們分彆應用于柱坐標繫及毬坐標繫下的流體運動微分方程組的推導過程中。結果錶明:如果將柱坐標繫及毬坐標繫下基矢量的物質導數公式作為基本公式使用,則可以使上述坐標繫下流體運動微分方程組的推導過程得到很大程度的簡化。
추도주좌표계급구좌표계하류체운동미분방정조통상채용적방법시근거시량형식적운동미분방정식,이용물질도수적기본공식화정교곡선좌표계각기시량적편도수공식래진행,추도과정상당번쇄,우기재교학과정중,재과당내완성상술구체추도과정궤호시불가능적。위료심조일충간첩적추도방법,본문의거기시량물질도수적기본공식,계산득출료주좌표계급구좌표계하적기시량물질도수공식,병장타문분별응용우주좌표계급구좌표계하적류체운동미분방정조적추도과정중。결과표명:여과장주좌표계급구좌표계하기시량적물질도수공식작위기본공식사용,칙가이사상술좌표계하류체운동미분방정조적추도과정득도흔대정도적간화。
The methods usually used for derivation of fluid motion differential equations in cylindrical coordinates and spherical coordinates are based on the vector form of fluid motion differential equation, by using the basic formula of the material derivative and the partial derivative formulae of orthogonal curvilinear coordinates base vectors. The derivation process is very complex, especially in the teaching, it is almost impossible to complete the above specific derivation process in the classroom. In order to find a simple derivation method, based on the basic formulae of base vector material derivative, it is calculated that the base vector material derivative formulae in cylindrical coordinates and spherical coordinates, and they are applied to derivation process of fluid motion differential equations in cylindrical coordinates and spherical coordinates. The results show that:if the base vector material derivative formulae of cylindrical coordinates and spherical coordinates are used as basic formulae, then the derivation process of fluid motion differential equations in above coordinates will be simplified greatly.