Tip clearance

About: Tip clearance is a research topic. Over the lifetime, 2637 publications have been published within this topic receiving 32671 citations.

Fan and motor housing

Abstract: Our invention relates in general to a fan and motor housing and more particularly to a fan and motor housing for an axial flow fan. An object of our invention is the provision of a fan and motor housing in which the motor and fan are so mounted and aligned within the housing that the tip clearance...

Numerical simulation of unsteady tip clearance flow in an isolated axial compressor rotor blades row

Abstract: Three-dimensional unsteady numerical simulations were carried out to analyse tip clearance flow in a low-speed isolated axial compressor rotor blades row. A flow solver has been used for the curren...

Performance of two 10-lb/sec centrifugal compressors with different blade and shroud thicknesses operating over a range of Reynolds numbers

Abstract: Centrifugal compressors often cannot be directly scaled to very small flow sizes because of structural and manufacturing limitations. The inability to directly scale all design parameters leads to a performance loss other than that which can be associated with the lower Reynolds number. A 10-lb/sec centrifugal compressor was scaled down to 2-lb/sec where adjustments to blade and shroud thickness and fillet radii were required. The modified 2-lb/sec compressor was then directly scaled back up to 10 lb/sec so that the effect of the modifications could be determined. The performance of the two 10-lb/sec compressors is compared over a range of speed and mass flow. The effect of variations in Reynolds number, impeller tip clearance, and shroud thickness on compressor performance is also presented.

An Experimental and Numerical Investigation Into the Effects of Squealer Blade Tip Modifications on Aerodynamic Performance

Abstract: Gas turbine blades using the so-called squealer tip configuration represent a majority of the high-pressure first stage blades in service. The squealer tip in its most basic format is simply a two-tooth labyrinth seal projecting from the blade tip towards the stationary shroud or casing. As with all blade tip configurations, the geometry is a compromise between aerodynamics, cooling, mechanical stress, durability, and repair. While many proposed blade tip innovations involve more complex geometries, this study seeks to determine if a simpler geometry, other than a flat tip, can provide equivalent aerodynamic performance with a reasonable chance of satisfying all other design factors. Using an annular sector blade cascade, total pressure loss surveys are measured with three blade tip geometries, the standard squealer tip, a single-sided suction side seal strip, and the single-sided strip with a pressure side winglet added. The same cascade is modeled numerically as a periodic passage for each of the geometries tested. Experiment and simulation both utilize all blade tip cooling flow injection locations and nominal magnitudes, as well as a constant tip clearance above the suction side seal strip. Experimental data show that the removal of the pressure side seal strip reduces the area-averaged total pressure loss slightly, while the addition of a winglet returns the performance to the baseline result. Numerical predictions indicate essentially equal performance for all geometries. The numerical results provide insight into the loss mechanisms of both the tip leakage flows and the coolant injection flows. This study, when combined with literature data on heat transfer and cooling, concludes that the simpler single-sided suction seal strip is better overall than the commonly employed squealer tip.Copyright © 2013 by ASME