Effectiveness measurements for a cooling film disrupted by a single jet with wall plunging
Abstract
Experimental measurements of the effectiveness downstream of a slot airflow with the jet airflow normal to the wall were performed in a wind tunnel. The separate and combined effects of the slot and jet airflows with and without wall plunging on the effectiveness and flow characteristics are presented over a range of slot and jet airflow conditions relevant to gas turbine combustors. The slot consisted of three rows of holes inclined at 10 degrees to the main airflow. The jet center line was positioned one, two and three diameters downstream from the slot exit. The jet diameter corresponded to five slot heights. Three wall plunge heights were used and corresponded to : 02, 0.4 and 12 jet diameters. The main airflow was constant at a Mach number of 0.05 and various combinations of the slot mass velocity ratio (0.5, 1.0 and 1.5) with the jet mass velocity ratio (0.5, 1.0 and 2.0) were tested. The effectiveness measurements covered an area eight jet diameters downstream of the slot exit by four jet diameters laterally. The results show that the major interactions between the three airflows occur downstream of the jet center line in a small region about three diameters long and two diameters wide. In general, such interactions reduce the effectiveness by up to forty percent when compared to the values with no jet injection. The combined and the separate effectiveness of the slot airflow and of the jet airflow are presented.
- Publication:
-
In AGARD Heat Transfer and Cooling in Gas Turbines 10 p (SEE N86-29823 21-07
- Pub Date:
- September 1985
- Bibcode:
- 1985htcg.agarS....B
- Keywords:
-
- Air Cooling;
- Combustion Chambers;
- Film Cooling;
- Gas Injection;
- Gas Turbines;
- Hole Geometry (Mechanics);
- Jet Flow;
- Wind Tunnel Tests;
- Effectiveness;
- Flow Characteristics;
- Flow Velocity;
- Slots;
- Turbulence Effects;
- Fluid Mechanics and Heat Transfer