Question

7) Explain the principle of measuring flow velocity using a pitot tube in a low-speed wind tunnel? (draw a schematic of the measurement, and write out the formulas for calculating the velocity)

Answer 1

Velocity Meas anement Using Pitol Tube Air Flow -Pudot Static tube Duct wall Eight 0.04 in holes 90 dea btcom ain blow circling olen Tube sp cstatic Pressuree) Potential energy put into the system Ve C Velocity Pressure) is the preessure along the line of the flow from ain blowing through the duct TP (Total Pressurce) ve TP= setup Manometer we asean Description inner As shown in tigunc TP is measured the otten tube using of pitot tube and sp measured using outen tube of pitot tube. When the inner and outer tube ends connected manometen get the vp. #for low velocity it is preferable to inclined tube manometen instead of U fube manometen. Calculations of velocity After taking relocity pressure readings, at various frovense points, the velocity conesponding to each point is calculated as Illows: V (m/s) > cp / 2Xq81X40 (p= Pidof Tube co-allicent =0.85 AP z velocity pressure PXM RXT po Absolule gas pressure, mouc M = Molecular Wt of gas , glamode, ben oin M23:12 T - Gas, Tempeneture, k R= Gus constant, 841.84 mm WC mo lng molek lugnole fn mmwo V= NF Bas Density , 19 m3