Tuesday, October 15, 2019

Velocity Distribution of a Circular Air Jet Lab Report

Velocity Distribution of a Circular Air Jet - Lab Report Example 7.3 Repeat the procedure for x=10D 7.4 The graphs should be symmetrical about the centerline. Decide for which graph, which value for y is at the center so that by subtraction, it is possible to plot V against radius r, measured from the centerline of the jet. 8 Analysis 8.1 Replot small versions of the three v, y curves on a plan view, identify and label (i) the edge of the jet (ii) the core, in which the air velocity is v0 (iii) the mixing region, where v is less than v0 8.2 From the plan view measure the divergence angle of the jet 8.3 Plot the centerline velocity distribution 8.4 Calculate q0, the volume flow rate leaving the nozzle, in m3s-3. It reasonable to assume that v0 is constant in the nozzle exit plane. 8.5 Calculate q10, the volume flow rate at x = 10D. In this case the air velocity is not constant thus it is necessary to integrate to find the volume flow rate. 9. Results of the air jet experiment: Air Jet v distribution x=1D pitot position (mm) inches mm 0 0.875 22.225 20 0.87 22.098 40 0.875 22.225 60 0.875 22.225 80 0.86 21.884 100 0.8 20.32 150 0.61 15.494 200 0.44 11.176 250 0.24 6.096 300 0.24 6.096 350 0.18 4.572 400 0.145 3.683 450 0.11 2.794 Air Jet v distribution x=2D pitot position (mm) inches mm 0 0 0 10 0.01 2.254 15 0.09 2.286 20 0.51 12.954 25 0.84 21.336 30 0.84 21.336 35 0.795 20.193 40 0.765 19.431 45 0.48 12.192 50 0.12 3.048 55 0.05 1.27 60 0 0 Air Jet v distribution x=10D pitot position...However, in this experiment the error can be considered as negligible A fan supplies air to a nozzle, which can provide a circular uniform jet of air. The nozzle is 30 mm in diameter. The velocity distribution in the jet is measured using a pitot static tube. The Pitot-static tube can be traversed across the jet diameter and also across its length by sliding the support against a millimeter scale to record its position. The pitot static tube is connected to an inclined manometer. 7.2 Measure the air velocity at points along the horizontal diameter at x=2D. Plot the variation of v with y as you take your readings. Use your judgment over how many points you need, ensuring that you locate the endpoints at the edge of the jet 7.4 The graphs should be symmetrical about the centerline. Decide for which graph, which value for y is at the center so that by subtraction, it is possible to plot V against radius r, measured from the centerline of the jet. The pressure in the center of the jet is higher at the point of origin. The pressure stabilizes further away to the point of origin to match the surrounding pressure and hence the jet spreads out as it flows in order to reduce its density.

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