The Preston tube in adiabatic compressible flow

✍ Scribed by P. J. Finley; L. Gaudet

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 234 KB
• Volume: 19
• Category: Article
• ISSN: 0723-4864
• DOI: 10.1007/bf00193859

✦ Synopsis

A new procedure for the reduction of Preston tube data is introduced, based on the van Driest transformation. It appears to give results agreeing with the better calibration experiments, although a significant assumption in its derivation is violated.

List of symbols

Ms

Mach number sensed by Preston tube Me Friction Mach number (= udwall sound speed) R Gas constant Tw Wall temperature d Diameter of Preston tube h Height of effective centre of Preston tube Ap Preston tube pressure difference reading Api Equivalent incompressible Preston tube reading Pw Wall pressure r Recovery factor (=0.896) u~ Friction velocity ( = [zJwall density] 1/2) ct Empirical constant allowing for departure from Crocco temperature-velocity correlation ( = 0.975) y Specific heat ratio v Fluid kinematic viscosity zw Wall shear-stress