Heat Transfer, Hydrodynamics and Pressure Drop in the Model of a Blade Leading Edge Cyclone Cooling

Abstract

The heat transfer, hydrodynamics and pressure drop have been studied experimentally at the air swirling flow in the round tube with 90° exit bend, simulating the blade cyclone cooling. The flow was supplied into the test section from the closed circular plenum through one or two tangential slots (swirl generators) made on the round tube surface. The flow angle to the first swirl generator was 60° (β = 0° is the “classic” tangential inlet). The following three configurations, reflecting the actual blade design, were studied, namely: (i) the tube with one swirl generator and open exit, (ii) the tube with one swirl generator and 90° exit bend, (iii) the tube with two swirl generators and 90° exit bend. The Reynolds number, based on the average axial velocity and tube internal diameter was ranged from 40000 to 105000. The surface streamline swirl flow angle, static and total pressure excess, heat transfer and pressure losses in the round tube, swirl generator area and exit bend were measured. In terms of the heat transfer rate the best results has demonstrated the configuration with one swirl generator and 90° exit bend.

Heat Transfer Enhancement for Turbine Blade Internal Cooling

“…By altering the inlet of the jets, the authors were able to generate a more uniform heat transfer distribution with average Nusselt number ratios approaching 3.0 within the rectangular, swirl chamber. In swirl chambers used to model leading edge cooling channels, swirling flows were shown to provide a thermal performance comparable to both continuous and broken V-shaped ribs [95,96]. Therefore, the heat transfer enhancement is realized without modifying the surface of the cooling channel (the walls of the swirl chamber where smooth).…”

Bewertung neuer Verfahren zur K"uhlung von Turbinenrotorschaufeln. Infrarotthermographie bei maschinen"ahnlichen Randbedingungen

“…Drallerzeuger,Khalatov et al (2000) Axiales Leitgitter 30°,Ahmadvand et al (2010) Axiales Leitgitter 60°,Ahmadvand et al (2010) Tang. Drallerzeuger div.,Khalatov et al (2011) Zyl. Dellen,Xie et al (2010) Zyl.…”