Accession Number : AD0628630

Title :   UNCONVENTIONAL METHODS FOR INFLUENCING FLUID FLOW. PART V. FLUID PRESSURE TRANSIENTS IN A TAPERED LINE.

Descriptive Note : Final rept. Jun 64-Jul 65,

Corporate Author : CARNEGIE INST OF TECH PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Tarantine,Frank J.

Report Date : NOV 1965

Pagination or Media Count : 137

Abstract : The study includes both an experimental and theoretical analysis of the transient wave behavior through an inviscid liquid filled, rigid tapered line subjected to both step and pulse inputs. The primary objective is to determine the applicability of a tapered line to attenuate the pressure surge associated with 'water hammer.' The analytical approach used is to divide a smoothly tapered section into a finite number of uniform lines of different characteristic impedances to form an approximation of the distributed parameter model readily solved by digital-computer computation. Three taper functions are studied in detail (linear, linear area and exponential), with two different terminations (long uniform line and reservoir). A step line is also studied, for which the method is exact. To verify the analytical approach and results, experiments were performed using water in a four step line made of copper tubing varying in diameter from 1/2 in. to 1 in. A special valve arrangement was designed to insure quick closure with minimum shock. Excellent experimental agreement was obtained. The results show that a tapered section can be used to reduce the pressure surge of 'water hammer' when the line is terminated by a reservoir. (Author)

Descriptors :   (*FLUID FLOW, CONTROL SYSTEMS), (*PRESSURE, ATTENUATION), TAPER, LIQUIDS, FUNCTIONS(MATHEMATICS), PIPES, VALVES, HYDRAULIC EQUIPMENT, REDUCTION

Subject Categories : Hydraulic and Pneumatic Equipment
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE