ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Numerical Investigations on Combined slot and effusion Film cooling of an Annular combustor Liner
This paper reports the results of a numerical study on film cooling of an annular combustor liner with a combined slot and effusion geometry using three-dimensional steady state RANS approach. The combined film cooling geometry is realised by merging a slot fed by three-dimensional coolant jets (3D slot) with an effusion array. After performing grid convergence and validation study for the numerical model, the film cooling performance of both the two-dimensional planar slot and three-dimensional slot in the combined film method is compared at the
same coolant mass flow rate to differentiate their cooling
behavior. It is observed that at any given flow condition,
the planar slot is over predicting effectiveness by more
than 20% as compared to the 3D slot in the range of X/S
= 0 to 20, where X/S is the non-dimensional streamwise
distance from slot exit. The staggered pattern of effusion
jets is seen to provide higher cooling than inline pattern.
In view of this, further numerical studies are carried out
with the three-dimensional slot coupled with the staggered
effusion array. It is observed that the film effectiveness
has a non-linear trend over a range of Mass Flow Ratios (MFRs) where the maximum laterally averaged adiabatic effectiveness is obtained at MFR = 5 for a blowing ratio of 1.2.