Air flow analysis and effect of angle on rotation vane blade trough 90° pipe bend

Abstract

The usual problem occurs when fluid flow pass through elbow or 90° pipe bend is that secondary flow will exist which then lead to high pressure drop. The high pressure drop happen will affect the elbow which is erosion will appear. To overcome this problem, a rotation vane blade with different angles are installed at the pipe. The rotation vane blade will reduce the pressure drop that happened. In this paper, analysis of air flow through 90 pipe bend and the effect of angle rotation vane blade toward it is investigated. The process of the investigation is made through experiment. The inlet velocity used in this experiment are 1.20, 1.30, 1.40, 1.45 and 1.50 m/s. Furthermore, all the inlet velocity produced turbulence flow. Then, rotation vane blade of angle 18° and 33° are installed between the pipes by turn before the 90° pipe bend. U-tube manometer are attached at two places which is Section A-A (before elbow) and Section B-B (after elbow). From this experiment, elevation heights that measured by u-tube manometer of the two sections which are located before and after the 90 pipe bend are recorded. Next, the elevation heights will be used in the Bernoulli equation in order to calculate the velocity distribution at all sections, pressure distribution at all sections and pressure drop between both sections. The result of this experiment show that the rotation vane blade produced slower velocity at section B-B and higher pressure at section B-B. Pressure drop between both sections A-A and B-B is lower when using larger angle of rotation vane blade (33°).