Accession Number : AD0688910
Title : RESEARCH ON ADVANCED GASDYNAMIC TEST FACILITIES. PART I. THEORETICAL AND EXPERIMENTAL STUDIES OF THE ISENTROPIC COMPRESSION TUBE.
Descriptive Note : Scientific interim rept. 1 Jul 66-31 Mar 68,
Corporate Author : CORNELL AERONAUTICAL LAB INC BUFFALO N Y AERODYNAMIC RESEARCH DEPT
Personal Author(s) : Stoddard,Frank J.
Report Date : JAN 1969
Pagination or Media Count : 84
Abstract : The report describes the current status of the theory of the isentropic-compression tube and discusses several experiments which have been conducted in a pilot facility. The theoretical portion deals with two possible techniques, the braked-piston and the free-piston, for producing the isentropic flow. According to theoretical analysis, an approximation to a focused, nonsteady, isentropic-compression wave can be produced with the braked-piston method which involves a mechanically simple modification to the motion of an otherwise freely moving piston. This method would provide two distinct isentropic test flows at different positions in the tube. In the free-piston method, no modification to a free-piston trajectory is necessary but only one test region is produced. The discussion of the experiments deals with the construction and testing of a low-pressure pilot facility. It is shown that the compression process in the pump tube is very close to isentropic. Initial attempts at producing an isentropic flow using the free-piston method are described. It is shown that a close approximation to the theoretically predicted flow was achieved although the flow duration was smaller than expected. (Author)
Descriptors : (*SHOCK TUBES, PERFORMANCE(ENGINEERING)), TEST FACILITIES, PRESSURE, ENTROPY, CONSTRUCTION, AERODYNAMIC CHARACTERISTICS, SHOCK WAVES, HELIUM, THEORY
Subject Categories : Test Facilities, Equipment and Methods
Distribution Statement : APPROVED FOR PUBLIC RELEASE