Brard 
NOMENCLATURE 
l, OPERATORS 
-(.3 3 3 oe 
Vv = ome Go ), (the axes X11 X59 X, make a right 
1 Zz 3 
handed system). 
2 ; 
A =V Laplacian operator 
A Symbol of vectorial multiplication. 
2. VORTEX FILAMENTS AND VORTEX SHEETS 
1g Vortex filament 
d DB Element of area of a vortex sheet 
eae The two sides of ‘D 
Infinitely small thickness of the vortex sheet 
Unit vector normal to the sheet in the direction from pe 
towards ae 
5 
Vv Velocity of a fluid point 
@ Curl of Vv 
Sea ER — > — 
T Limittof ¢€@ when e-.0\. T =(T - I") + 1" dm sectia aan 
Vi, ViEE; 
> 2 : ; ; 4 
T Unit vector tangent to 2 in the direction of TF 
=> = 
WP) - V(P._), (or V(M - V(M_) : jump of V through > from 
ee “to e: ise ie M: Z M.), P (or M ), P. (or M.) be- 
1 e e i i 
longing to Bee ae 3 respectively, 
T = -n Ot 7) 
ee Line on nS orthogonal to nel Aa 
—- 
ip Circulation of V ina closed circuit 
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