# Accession Number:

## AD0653946

# Title:

## THE EFFECT OF FROUDE NUMBER ON THE TWO-DIMENSIONAL FLOW OF AN INVISCID DENSITY-STRATIFIED LIQUID PAST A SLENDER BODY,

# Descriptive Note:

# Corporate Author:

## BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH FLIGHT SCIENCES LAB

# Personal Author(s):

# Report Date:

## 1967-04-01

# Pagination or Media Count:

## 27.0

# Abstract:

The linearized equation governing the flow of a density-stratified liquid is used, small velocity perturbations and an exponential variation of density with height having been assumed. The effect of accelerative forces is included in addition to gravity forces thus, there is no restriction to small Froude numbers. A simple transformation of the partial differential equation puts it in a form analogous to the small Froude number equation studied in earlier reports. Solutions are then obtained by analogy to small Froude number solutions. Two types of singularities are considered, the vortex lift producing and the pseudo-dipole thickness and lift producing. The latter is used in place of a simple dipole producing thickness only because pseudo-dipoles on a horizontal plane located in a closed channel symmetrically or in an infinite fluid produce a body which is symmetrical top to bottom. The lift force is required to maintain this body symmetry at non-zero Froude numbers, but disappears as the Froude number approaches zero. The effect of Froude number on upstream disturbances, lee waves and wave drag is indicated. Author

# Descriptors:

# Subject Categories:

- Fluid Mechanics