In region 2, the total loss in impeller without tip clearance
is composed only of secondary loss, incidence loss and skin friction loss.
In this study, the squealer height is 0.615 mm while the tip gap height is 0.615 mm which corresponds to a tight tip clearance
(t/h = 0.5%).
(2) Inlet Lip Radius (3) Diffuser Angle (4) Diffuser Length, which are defined as shown in the Figure 1
But guide vanes and tip clearance
were omitted for simplification in their structure simulation, which could not reflect the actual characteristics of the pump.
The grid independence was examined by the tip leakage flow rate with the seal teeth number being 5 and the size of tip clearance
being 0.75 mm.
I wrote about tip clearance
and its control in an earlier article , Tightening tip clearances
and keeping them under control is a constant worry for OEMs and operators.
The near-stall conditions with a smooth casing (without a casing treatment) can induce vortex flows originating from the tip clearance
flow crossing the tip gap.
The tip clearance
between the impeller and the casing with a clearance of 3 mm is also included.
Two sensor types (capacitive and microwave) are employed to capture the blade tip clearance
both for health monitoring and comparison purposes.
Innovative designs nave been developed to allow closed-loop control of the tip clearance
by both thermal and mechanical systems.
The copilot noted that the blade tip clearance
was going to be close, but made no comment to the HAC who was talking on the radio.