Unsteady Effects of Dissociative Cooling Under High-Stagnation-Point Heat Loads

1998 ◽  
Vol 35 (5) ◽  
pp. 633-638 ◽  
Author(s):  
Benjamin P. Lacy ◽  
Philip L. Varghese ◽  
Dennis E. Wilson
Keyword(s):  
Stagnation Point ◽  
Unsteady Effects ◽  
Heat Loads

Unsteady Effects in Turbine Tip Clearance Flows

2000 ◽  
Author(s):  
Anil Prasad ◽  
Joel H. Wagner
Keyword(s):  
Tip Clearance ◽  
Time Resolved ◽  
Vena Contracta ◽  
Deviation Measurement ◽  
Blade Tip ◽  
Unsteady Effects ◽  
Heat Loads ◽  
High Work ◽  
Careful Comparison ◽  
Made In

The present study is concerned with the unsteady flow field on the blade outer air seal segments of high-work turbines; these segments are installed between the blade tip and outer casing and are usually subjected to extreme heat loads. Time-resolved measurements of the unsteady pressure on the blade outer air seal are made in a low-speed turbine rig. The present measurements indicate the existence of a separation zone on the blade tip which causes a vena contracta to form at the entrance of the tip gap. In addition, a careful comparison between the ensemble-averaged pressure measurement and the corresponding result from steady computation suggests that the pressure on the blade outer air seal can largely be described as being due to a steady flow (in the rotating frame) sweeping past a stationary probe. The ensemble deviation measurement indicates that unsteadiness (from one revolution to the next) is confined to the tip gap.

Unsteady Effects in Turbine Tip Clearance Flows

2000 ◽  
Vol 122 (4) ◽  
pp. 621-627 ◽  
Author(s):  
Anil Prasad ◽  
Joel H. Wagner
Keyword(s):  
Tip Clearance ◽  
Time Resolved ◽  
Vena Contracta ◽  
Deviation Measurement ◽  
Blade Tip ◽  
Unsteady Effects ◽  
Heat Loads ◽  
High Work ◽  
Careful Comparison ◽  
Made In

The present study is concerned with the unsteady flow field on the blade outer air seal segments of high-work turbines; these segments are installed between the blade tip and outer casing and are usually subjected to extreme heat loads. Time-resolved measurements of the unsteady pressure on the blade outer air seal are made in a low-speed turbine rig. The present measurements indicate the existence of a separation zone on the blade tip, which causes a vena contracta to form at the entrance of the tip gap. In addition, a careful comparison between the ensemble-averaged pressure measurement and the corresponding result from steady computation suggests that the pressure on the blade outer air seal can largely be described as being due to a steady flow (in the rotating frame) sweeping past a stationary probe. The ensemble deviation measurement indicates that unsteadiness (from one revolution to the next) is confined to the tip gap. [S0889-504X(00)02304-7]

Sign in / Sign up

Export Citation Format

Share Document