Impellers with shorted blades are widely used in centrifugal pumps and compressors. Experimental and numerical investigation of influences of shorted blades circumferential positions on centrifugal pump performance are carried out
In the experimental work, a test rig with measuring facilities in order to get performances in different conditions are conducted. Four impeller configuration shorted blade circumferential positions; mid-way, near suction side, near pressure side and near bot suction and pressure sides are manufactured. The pump head, flow rate, and shaft power re measured at different rotational speeds for each pump configuration to show the effects of shorted blades position on pump performance.
A mathematical model using FLUNET software is constructed to predict the flow field characteristics in the impellers passage. A hybrid mesh is created using FLUENT's pre-processor GAMBIT. The realizable K-ᵋ turbulent model and unstructured grids are used
The experimental results for five different impeller configurations show that, better performance is obtained by putting the shorted blade midway inside the impeller channel, both the pump head and efficiency have the highest improvements at different speeds. Impeller with shorted blade near pressure side shows improvement of pump efficiency at all speeds comparing to standard impeller but lower than the improvement of midway shorted impeller. While impeller with shorted blade near suction side has negative effect in improving pump performance.
Based on numerical results. The static pressure raises from inlet to outlet in all impeller configurations. The static pressure and flow velocity distribution at impeller exit become more uniform for Impellers with shorted blade
|
