Citation
Lissaman, Peter B. S. (1966) A linear solution for the jet flap in ground effect. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd09302002123622
Abstract
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The paper presents the solution of the problem of the Jet Flap airfoil in a plane inviscid flow in the presence of the ground. The basic flow equations are derived and the nonlinearity of the boundary conditions are discussed. The problem is then linearized as in thin airfoil theory. By a conformal transformation the flow field is mapped into one having very simple geometry. The singularities of the mapping are identified and the asymptotic character of the flow fields derived. The basic integrodifferential equation is developed; this has singular Hilbert type kernels and discontinuous boundary conditions. By considerations of the second order effects, significant relationships between the lift slopes with angle of attack, with jet angle and jet coefficient are developed. These are further simplified by introduction of a new geometrical parameter developed from the mapping. The lift coefficient of the airfoil is expressed in three parts, of which two may be evaluated in simple closed form. The remaining part depends on the solution of the integrodifferential equation. This equation is then solved at N points by assuming a piecewise smooth velocity distribution and generating an N x N matrix: numerical results are obtained from an IBM 7094 computer. It is proved that this approximation converges to the exact solution. The limiting cases, when the height to chord ratio, h/c, or jet coefficient, C[subscript J], approach zero or infinity are developed, exploiting the decomposition of the lifting components; and an asymptotic result for small C[subscript J] is presented. A linearized theory for wake blockage is given, which also gives an indication of the restrictions on the various parameters implied by the basic linear approach. The results for [...] correlate excellently with Spence's solution for [...]. For low values of h/c the results agree quite well with the limited applicable test data.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Degree Grantor:  California Institute of Technology 
Division:  Engineering and Applied Science 
Major Option:  Aeronautics 
Thesis Availability:  Public (worldwide access) 
Research Advisor(s): 

Group:  GALCIT 
Thesis Committee: 

Defense Date:  7 December 1965 
Record Number:  CaltechETD:etd09302002123622 
Persistent URL:  http://resolver.caltech.edu/CaltechETD:etd09302002123622 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  3830 
Collection:  CaltechTHESIS 
Deposited By:  Imported from ETDdb 
Deposited On:  30 Sep 2002 
Last Modified:  22 Oct 2018 16:44 
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