Session: Student Poster Competition

Submission Number: 187145

Vki Ls89 Vane Leading Edge Film Cooling Using Sweeping Jet 

Modern gas turbine engines continue to evolve in response to the demand for higher thrust levels, improved thermal efficiency, and reduced specific fuel consumption, all of which are necessary for achieving more economical and reliable operation. These objectives require operation at elevated turbine inlet temperatures, which in turn place severe thermal loads on hot-gas-path components. Consequently, the development and optimization of effective cooling strategies remain a key area of research. Among the available internal and external cooling techniques for turbine vanes, film cooling has been established as the most practical and efficient external method for providing surface protection and enhancing component life. Recent advances in additive manufacturing have enabled the realization of complex cooling configurations that were previously difficult to fabricate, including unsteady jet concepts such as sweeping jets generated by fluidic oscillators. A sweeping jet is a self-excited oscillatory flow produced without any moving mechanical parts. The periodic switching motion of the jet generates alternating vortex structures, which inhibit the formation of classical contra-rotating vortex pairs typically associated with steady cylindrical cooling holes. This altered vortex topology leads to improved lateral spreading and surface coverage of the coolant. In addition, sweeping jet holes exhibit a non-conventional dependence on blowing ratio, where lower blowing ratios have been reported to yield higher film cooling effectiveness, thereby reducing the overall coolant mass flow requirement.

The leading edge of a turbine vane represents one of the most thermally critical regions due to the presence of a stagnation point, strong pressure gradients, and rapid flow acceleration. For this reason, cooling holes are commonly placed close to the leading edge. In realistic turbine cascades, however, the local vane geometry restricts the allowable size and shape of cooling holes. For fluidic oscillators, such geometric constraints directly influence the oscillation frequency, which plays a crucial role in governing coolant mixing, diffusion, and ultimately surface temperature reduction. The present numerical study investigates the influence of sweeping-jet size on film cooling performance at the leading edge of the VKI LS89 nozzle vane cascade. Two different sweeping-jet geometries are considered to examine the effect of oscillator scale on the resulting unsteady flow structures and cooling effectiveness. This poster shows the cooling effectiveness on the vane surface obtained from the sweeping jet hole. To help understand the unsteady flow phenomena, the iso-surfaces of Q-criterion are also presented. The poster also focusses on formation of complex flow structures induced by coolant and mainstream flow interactions. Further details will be presented in the poster.

Presenting Author: Daksh Gupta Indian Institute of Technology Kharagpur

Presenting Author Biography: Presenting author is a third year undergraduate student at Indian Institute of Technology Kharagpur. He has contributed to a publication on DNS parallelisation technique and currently submitted a technical paper to Turbo Expo 2026.

Authors:

Daksh Gupta Indian Institute of Technology Kharagpur
Hitesh Sharma Indian Institute of Technology Kharagpur
Chetankumar Mistry Indian Institute of Technology Kharagpur