Accession Number : AD0017495


Title :   DETERMINATION OF THE EXTERNAL CONTOUR OF A BODY OF REVOLUTION WITH A CENTRAL DUCT SO AS TO GIVE MINIMUM DRAG IN SUPERSONIC FLOW, WITH VARIOUS PERIMETRAL CONDITIONS IMPOSED UPON THE MISSILE GEOMETRY


Corporate Author : CORNELL AERONAUTICAL LAB INC BUFFALO NY


Personal Author(s) : Ferrari, Carlo


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/017495.pdf


Report Date : Mar 1953


Pagination or Media Count : 70


Abstract : Formulas and processes are presented for determining the best shape for the external surface of an annular duct which produces a minimum amount of wave drag in supersonic flow under conditions invoked to ensure that the missile geometry will obey practical design requirements. The problem of the best shape is solved under the restrictions (1) that the area between the given inner contour of the body of revolution and the sought outer contour is a constant, and (2) that the volume comprised between the surfaces which are swept out when such inner and outer contours are rotated about the duct axis is a constant. Further distinctions are made in the treatment of this problem on the basis of the type of inner known duct shape given; in one case it is assumed that the annular duct will differ slightly from a cylinder, while in the other case it is assumed that the basic shape upon which the desired external duct contour is to be built up is fundamentally a frustum of a cone. The flow through the inside of the duct is not considered, and the internal oblique shock is assumed to be attached to the entrance lip; the trailing edge at the duct exit does not have a blunt face. Two distinct modes of attack are offered to attain the solution in all cases. One method is based on the use of Lighthill's W-function and gives the best contour shape and drag directly. The other method requires that a suitable distribution of supersonic sources be determined first; once the description of how these singularities vary along the x-axis is obtained, the best contour and the related drag are derived as auxiliary information. The connection between these results and those which would be obtained by use of 2- dimensional (Ackert) theory is also pointed out.


Descriptors :   *GUIDED MISSILES , *AERODYNAMIC DRAG , *WING BODY CONFIGURATIONS , SHOCK WAVES , ATTACK , SHAPE , EXTERNAL , SUPERSONIC CHARACTERISTICS , PRESSURE DISTRIBUTION , CONTOURS , TRAILING EDGES , CONICAL BODIES , EXITS , SUPERSONIC FLOW , GEOMETRY , SURFACES , INTERNAL , DUCTS


Subject Categories : Guided Missile Dynam, Config & Cntrl Surfaces


Distribution Statement : APPROVED FOR PUBLIC RELEASE