LATERAL MOTION OF A SLENDER BODY BETWEEN TWO PARALLEL WALLS

The method of matched asymptotic expansions is used to determine the lateral flow of an ideal fluid past a slender body, when the flow is constrained by a pair of closely spaced walls parallel to the long axis of the body. In the absence of walls, the flow field would be nearly two-dimensional in the cross-flow plane normal to the body axis, but the walls introduce an effective blockage in the cross-flow plane, which causes the flow field to become three-dimensional. Part of the flow is diverted around the body ends, and part flows past the body in the inner cross-flow plane with a reduced 'inner stream velocity'. An integro-differential equation of identical form to Prandtl's lifting-line equation is derived for the determination of this unknown inner stream velocity in the cross-flow plane. Approximate solutions are applied to determine the added mass and moment of inertia for a accelerated body motions and the lift force and moment acting on a wing of low aspect ratio. It is found that the walls generally increase these forces and moments, but that the effect is significant only when the clearance between the body and the walls is very small.

• Corporate Authors:

  Cambridge University Press

  32 Avenue of the Americas
  New York, NY  United States  10013-2473
• Authors:
  • Newman, J N
• Publication Date: 1969

Media Info

• Features: References;
• Pagination: p. 97-115
• Serial:
  • Journal of Fluid Mechanics
  • Volume: 39
  • Issue Number: Pt1
  • Publisher: Cambridge University Press

Subject/Index Terms

• TRT Terms: Coefficients; Mass; Navigation; Wall effect
• Uncontrolled Terms: Blockage
• Old TRIS Terms: Added mass; Shallow water effects
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00050901
• Record Type: Publication
• Source Agency: Massachusetts Institute of Technology
• Files: TRIS
• Created Date: Feb 15 1974 12:00AM