Combined 3D Flow and Heat Transfer Measurements in a 2-Pass Internal Coolant Passage of Gas Turbne Airfoils

Abstract

A study of the flow and heat transfer in a stationary model of a two-pass internal coolant passage is presented, which focuses on the flow characteristic effects on the wall heat transfer distribution. Results are given in the upstream fully developed region. Heat transfer measurements were made with a transient technique using thermochromic liquid crystal technique to measure a surface temperature. The technique allows full surface heat transfer coefficient measurements on all the walls. Flow measurements were made with a stereoscopic digital PIV system, which measures all three-velocity components simultaneously. The coolant passage model consists of two square ducts, each having a 20 hydraulic diameter length. The ducts are connected by a sharp 180° bend with a rectangular outer wall. 45° ribs are mounted in a staggered arrangement on the bottom and top walls of both legs. The height of the ribs is equal to 0.1 hydraulic diameters. They are spaced 10 rib heights apart. The flow and heat transfer measurements were obtained at one flow condition with an inlet flow Reynolds number, based on the hydraulic diameter, of 50,000. The paper presents detailed measurement results of the flow characteristics and of the heat transfer distribution in the upstream straight leg of the passage and describes how the main and secondary flows influence the heat transfer distribution in the fully developed regions of the channel.

Wall modeled Large-Eddy Simulations in rotating systems for applications to turbine blade internal cooling

“…The results of WMLES was compared to LES results by Abdel-Wahab [25] and experimental data by Chanteloup et al [33] as seen in Table 5 difference was observed with calculations without wall modeling. Despite these differences, TKE and ̅̅̅̅̅ contour plots were within 9% of LES.…”

“…Similarly, Chanteloup et al [33] did a study on 45 angled ribs at a bulk Reynolds number of 50,000 with e/D h of 0.1, and p/e of 10. Investigations were done based on the previous study by Han and Park [36].…”

“…LES was used to simulate the case with experimental data by Chanteloup et al [33] to validate results. The mesh size was 160 128 128 in x, y, and z directions where the first mesh point was placed at < 1 with 4 to 5 mesh points placed within 10 wall units.…”

Experimental Investigation of Heat Transfer in Two-Pass Coolant Passages With Ribs and Film Cooling Hole Ejection

“…Upstream of the bend, the heat transfer distribution is typical of fully developed flow region in channels with 45deg rib arrangements. It has been described in details in Rau [10] and Chanteloup et al [11]. For 0% extrac C = , the heat transfer distribution is quite repetitive from one rib module to another, indicating that it is in the fully developed region.…”

“…Rau [10] and Chanteloup et al [11] described the flow and heat transfer combination in fully developed regions of channel with 45deg rib arrangement. In Chanteloup et al [12], Chanteloup et al [13] and Chanteloup et al [14], the particle-image-velocimetry (PIV) measurement method was employed for the investigation of the flow field in models with film cooling holes and turning vane.…”