Session: 01-13 Inlet Distortion and Engine Operability II

Paper Number: 151869

Experimental Deduction of Restitution Coefficients of Different Sand Sizes in an Inertial Particle Separator System 

Rotorcraft engines frequently operate in harsh environmental conditions, exposed to the ingestion of foreign matter such as sand, dust, rain, and hail. These contaminants can significantly degrade engine performance and reduce its operational lifespan. To mitigate these adverse effects due to ingestion of foreign particles, Engine Particle Separators are employed to remove particles from the engine main flowpath. Inertial Particle Separator (IPS) systems are commonly utilised in gas turbine engines, which force particles separated by their inertia. Separation efficiency of IPS system is defined as the amount of separated particles divided by the amount of ingested particles. Separation efficiency is influenced by various factors, including airflow rate, surface profile and properties [1] and particle features [2].

Current study is a continuation of GT2023-103056 article [3] and focuses on the deduction of Coefficient of Restitution (COR) to understand the particle - wall interaction in detail. COR is a critical parameter that characterizes particle behaviour upon impact with a surface. The tangential and normal components of COR are key determinants of IPS particle separation efficiency. In the previous study, detailed aerodynamic validation was conducted on a test rig with an engine-like hardware and separation efficiency was attained through direct measurements for a sector model. Therefore current study aims at the experimental investigation of sand particle trajectories of varying sizes within an IPS system and to estimate their respective COR values. Obtained COR values are intended to be utilised as input for modelling wall interaction in numerical analyses.

To capture particle velocities before and after impact, Particle Trajectory Velocimetry (PTV) and Particle Image Velocimetry (PIV) techniques are employed in the test campaign. The article provides a detailed description of the experimental setup, methodology for COR calculation and wall interactions of particles of different sizes with a focus on their impact velocities, impact angles and COR values. At first glance, an examination of the test results indicates that smaller particles are accelerated by the flow, achieving higher impact velocities compared to larger particles. Consequently, smaller particles impact the outer dome of the IPS at points further from entry. In contrast, larger particles undergo multiple collisions with the walls near the IPS entrance, leading to a loss of both momentum. The findings reveal that smaller sand particles tend to follow the airflow, while larger particles exhibit behaviour independent of the flow.

 

References

1.      M.E. Taslim, A. Khanicheh, S. Spring (2009) A Numerical Study of Sand Separation Applicable to Engine Inlet Particle Separator Systems, Journal of the American Helicopter Society, Volume 54.

2.      D. Barone, E. Loth, P. Snyder (2017) Influence of Particle Size on Inertial Particle Efficiency, Powder Technology, Volume 318.

3.      A. Saat, H.E. Isik, A.Arslan, E. Erdem, Y. Kaptan (2023) Numerical and Experimental Approaches for Inertial Particle Separator Design, ASME Turbo Expo 2023

Presenting Author: Halime Esra Işık TUSAS Engine Industries (TEI)

Presenting Author Biography: Born in Bursa, Türkiye in 1996. Graduated from ITU Mechanical Engineering in 2019. She has been working as an aerodynamic engineer at TUSAS Engine Industry since 2021.

Authors:

Halime Esra Işık TUSAS Engine Industries (TEI)
Ahmet Saat TUSAS Engine Industries (TEI)
Erinç Erdem TUSAS Engine Industries (TEI)
Ahmet Arslan TUSAS Engine Industries (TEI)
Mustafa Perçin Middle East Technical University (METU)