Accession Number : ADA188818

Title :   Compressible Friction Coefficients in a Simulated Heat Pipe.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Holladay, Constance A

PDF Url : ADA188818

Report Date : Dec 1987

Pagination or Media Count : 80

Abstract : Research was performed to verify previously obtained friction coefficients for compressible, laminar and turbulent flow in a simulated heat pipe for intermediate mass injection and suction rates. The research was divided into two main parts: an experimental study and numerical study. In the experimental study, a simulated heat pipe consisting of a long porous tube with air injected into one end to simulate the evaporator and extracted from the other end to simulate the condenser was investigated. Axial static pressure variations for various air supply mass flow rates were measured. It was found that the friction in the pipe decreased the amount of pressure recovery at the end of the pipe and that this decrease became even greater with increased supply mass flow rate. The pressure distributions obtained in the experimental study were used as input for a numerical simulation in the numerical portion of this research. A steady, one-dimensional computer code was developed to simulate the porous pipe system used in the experimental study in order to calculate Mach numbers, axial Reynolds numbers, and friction coefficients along the pipe. The results obtained for the friction coefficients in the porous pipe system studied did not correlate with the values predicted by Bowman's expressions. They exhibited the general trend expected for the friction coefficient - axial Reynolds number product with Mach number.

Descriptors :   *FRICTION, *HEAT PIPES, *GAS FLOW, COEFFICIENTS, COMPUTER PROGRAMS, FLOW RATE, INJECTION, MACH NUMBER, MASS FLOW, MATHEMATICAL MODELS, NUMERICAL ANALYSIS, ONE DIMENSIONAL, PIPES, POROUS MATERIALS, PRESSURE, PRESSURE DISTRIBUTION, RATES, RECOVERY, REYNOLDS NUMBER, SIMULATION, STATIC PRESSURE, SUCTION, TUBES, TURBULENT FLOW, VARIABLE PRESSURE, THESES, COMPRESSIBLE FLOW, LAMINAR FLOW, MATHEMATICAL MODELS, COMPUTERIZED SIMULATION

Subject Categories : Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE