Accession Number : AD0753065

Title :   Temperaturverteilung in Hitzdraehten in Hochenthalpiestroemungen geringer Dichte (Temperature Distribution in Heating Wires in High Enthalpy Flows of Low Density),

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V PORZ-WAHN (WEST GERMANY)

Personal Author(s) : Fiebig,Martin

Report Date : 25 MAY 1972

Pagination or Media Count : 10

Abstract : The temperature distribution along hot wires in high-enthalpy low-density flows is calculated by analytical methods. The diameter of the wire is assumed to be small in comparison with the characteristic mean free path of the flow field. Forced convection, conduction, radiation and Joule heating are taken into account in the energy balance of the wire. The material properties of the wire are assumed to be linear functions of temperature. The exact solution of the highly nonlinear problem can be simplified considerably for very long and relative short wires. These simplifications are independent of the temperature difference over the wire. For long wires a linearisation of the problem is only possible for small ratios of total temperature difference to the maximum wire temperature. For short wires a linearization is appropriate even for arbitrary values of this ratio. The approximate solutions allow simple estimates which are of importance for the design of hot wires for high-enthalpy low-density flows. The accuracy of the approximate solutions can be calculated a posteriori by means of the exact solutions. (Author)

Descriptors :   (*FLUID FLOW, HEATING ELEMENTS), FLOW FIELDS, CONVECTION(HEAT TRANSFER), WEST GERMANY, ENTHALPY, TEMPERATURE

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE