Influence of mainstream turbulence on turbine blade platform cooling from simulated swirl purge flow

The Aero-Thermal Performance of Purge Flow and Discrete Holes Film Cooling of Rotor Blade Platform in Modern High Pressure Gas Turbines: A Review

“…Another investigation on the behaviour of a cooled rotor blade platform under simulated swirl purge flow conditions was presented by [18]: a PSP study conducted within a low-speed linear cascade on the cooling effectiveness was presented based on simulated swirl purge flow. Swirl ratio values from 0.4 (30 deg injection angle) up to 1 (90 deg injection angle, i.e., radial injection or no relative motion) were obtained installing a set of coolant hole plates equipped with 50 cylindrical holes of specific inclination in the tangential direc-tion inside of the slot.…”

“…A number of studies have shown that increasing the turbulence intensity level mainly leads to a reduced film cooling effectiveness. In [18] the film cooling effectiveness was measured inside a low-speed linear cascade as a function of the turbulence intensity and rotational effects induced by a simulated purge swirl vortex. The authors reported: (i) the beneficial effect of the MFR parameter lessened under rotation condition; (ii) in general, there was higher effectiveness for higher mainstream turbulence.…”

“…The main objective was to provide qualitative indications on the cooling level and trends of modern HPT cooling designs. [18] Exp. Re 1 = 2.5 × 10 5 0.5 ÷ 1.5 1.5 0.72 ÷ 13 S2-H3(c&s) Li et al, 2016 [17] Exp.…”

“…The former family of experimental facilities may simulate rotation effects through swirl motion or fin introduction. Most of these researches were carried out at Texas A and M University on a five-blade cascade test facility [13][14][15][16][17][18][19][20], at the University of Bergamo on a seven-blade cascade test facility [21][22][23][24][25][26] and at Whittle Laboratory of the University of Cambridge [27,28]. Meanwhile, the latter family of experiments (rotating platforms) were carried out in the TPFL-research turbine facility at Texas A and M University [29,30], in the CT3 compression tube turbine test rig at the von Karman Institute [31], at Ohio State University Turbine Test Facility (TTF) [32][33][34], at the LISA research turbine available at ETH Zurich [35,36] and, more recently, at the Large Annulus Rig (LAR) of the University of Bath [37,38].…”

“…Similarly, in Figure 3, some of the considered discrete cooling hole designs are gathered to illustrate their positioning within the blade channel, e.g., holes located on the fileted end wall along the blade pressure side as in [21] and distributed along the interplatform gap [24], downstream half of the passage towards the trailing edge as in [20,26,30] and over the whole platform, as in [13,14]. [22], (b) S2 [13] and (c) S1s [18].…”