The Experimental Investigation of Jet Fan Aerodynamics Using Wind Tunnel Modeling

1996 ◽  
Vol 118 (2) ◽  
pp. 322-328 ◽  
Author(s):  
K. R. Mutama ◽  
A. E. Hall
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Wind Tunnel ◽  
Initial Pressure ◽  
Tunnel Wall ◽  
Tunnel Ventilation ◽  
Significant Length ◽  
Complete Set ◽  
Jet Fan ◽  
Jet Oscillation

Jet fan aerodynamic behavior was investigated using wind tunnel modeling. Conditions were created to simulate mine and vehicular tunnel ventilation where these fans are finding increased application. Results showed that the ability of a jet fan to entrain air depends on its proximity to the tunnel wall. Moving the jet fan toward the wall increased the initial pressure drop below ambient in a significant length of the tunnel. This increased the volume of air entrained despite the existence of a large recirculation eddy or back flow whose size diminished as the jet fan was traversed toward the tunnel axis. When the jet fan was located at the tunnel axis the flow was very unstable close to the walls of the tunnel and it had a tendency to reverse itself with periods coinciding with the jet oscillation behavior. The complete set of measurements obtained are suitable for CFD code validation and modeling.

Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

2013 ◽  
Author(s):  
Jian Pu ◽  
Zhaoqing Ke ◽  
Jianhua Wang ◽  
Lei Wang ◽  
Hongde You
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Turbine Blade ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Flow Ratio ◽  
Lp Turbine ◽  
Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

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