Dynamic theory of a short hot wire normal to an incompressible airflow, constant resistance operation
✍ Scribed by De Haan, R. E.
- Publisher
- Springer
- Year
- 1971
- Tongue
- English
- Weight
- 989 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0003-6994
No coin nor oath required. For personal study only.
✦ Synopsis
The aim of the investigation was primarily the computation of the dynamical corrections on the static calibration curve. A brief aecount is given of the available analytical expressions for the b_eat transfer of a hot wire to the ambient airflow. The appropriate form is inserted in the small perturbation energy equation giving, with constant values of the characteristic parameters, a linear second order differential equation. A number of numerieal examples was eomputed from the exact solution yielding the influence of frequency on the sensitivity and the temperature distribution along the wire. The analysis is supplemented by a short review of some complicating factors not included in the linear theory. Nomenclature A , B , B " b C c d G Gr h I l le K n 3/I Nu, Nur coefficients of heat transfer; B' = 0.4BÜ °.4 temperature coefficient of electric resistanee 4bRol ~d~~w velocity of sound; speeifie heat diameter overall transconductance Grashof number heat transfer coeIficient heating current, fT + i = i q-{ eäo~ length of bot wire "cold length", ~C(V --~2)~-} Knudsen number Mach number Nusselt numbers