Eur. Phys. J. Plus (2021) 136: 1019
https://doi.org/10.1140/epjp/s13360-021-01999-4

Regular Article

An optimal design for S-shaped air intake diffusers using simultaneous entropy generation analysis and multi-objective genetic algorithm

Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran

^a m.yadegari@kntu.ac.ir

Received: 22 June 2021
Accepted: 25 September 2021
Published online: 11 October 2021

Abstract

Today, the use of high-efficient air intakes is one of the main interests in aviation devices. Uniform distribution of airstream at the compressor inlet has a pivotal influence on motor performance. Therefore, it is essential to evaluate the quality of airflow from the beginning area of the inlet duct to the delivery stage inside the engine. Moreover, the installation of air intake outside the fuselage of some aircraft necessitates the use of S-shaped air intakes. An appropriate design of the S-shaped air intake in order to reduce the inlet flow velocity is of potential importance. Regarding this, the present study aims to optimize the centerline radius of curvature, turning angle and the area ratio in S-shaped air intake diffusers in turbulent flow regimes by changing the geometric shape and simultaneous use of entropy generation analysis and multi-objective genetic algorithm. A hundred simulations are conducted for the radius of the centerline in the range of 210 to 305 mm, the turning angle in the range of 30.5° to 62.5° and the area ratio in the range of 1.076923 to 2.230769. The results show that in optimal cases R = 294.4 mm,  = 61.53° and AR = 1.44548655, the efficiency is improved by 23.68%, 6.28% and 11.07%, respectively, compared to the base case. In addition, the performance of the motor is reduced due to separation and non-uniform stream distribution.