Title of article :
Computational Analysis of Integrated Engine Exhaust Nozzle on a Supersonic Fighter Aircraft
Author/Authors :
Arif, I Department of Aerospace Engineering - College of Aeronautical Engineering - National University of Sciences and Technology, Islamabad, Pakistan , Masud, J Department of Mechanical Engineering - Air University, Islamabad, Pakistan , Shah, I Department of Aerospace Engineering - College of Aeronautical Engineering - National University of Sciences and Technology, Islamabad, Pakistan
Abstract :
A unique approach of analyzing jet exhaust nozzle integrated to aircraft and propulsion system is presented in
this paper. Engine exhaust nozzle is usually omitted in Wind Tunnel Testing and numerical analysis of
aircraft due to complexities involved in integration of nozzle and presence of high pressure / temperature
inside exhaust nozzle. Also, the flow properties are non-uniform and highly turbulent in the vicinity of nozzle.
Therefore, exhaust nozzle is usually analyzed in isolation and these results often lead to inaccuracies from
actual scenario where nozzle is integrated with aircraft and its propulsion system. This research aims to
integrate engine exhaust nozzle on a supersonic fighter aircraft and analyze its flow characteristics and
variation in performance parameters due to its integration. Engine propulsion characteristics and parameters
such as nozzle inlet temperature and total pressure have been analyzed through an in-house validated engine
analytical model developed by some of the authors of this study. In the first part of paper, exhaust plume
structure has been analyzed to study the flow behaviour (flow turbulence and flow distortion etc) at nozzle
exit. Later, nozzle performance parameters such as Exit Velocity, Nozzle Pressure Ratio (NPR), Engine
Pressure Ratio (EPR), and Engine Temperature Ratio (ETR) have been calculated when exhaust nozzle is
integrated with the aircraft. Finally, the results are compared and validated with analytical calculations to
compare the performance of nozzle when it is in isolation and when it is integrated on aircraft. It is observed
that nozzle flow has no significant effect on aircraft major surfaces such as fuselage, wing upper and lower
surfaces, and nose section. However, there is a prominent effect of exhaust nozzle flow on horizontal
stabilizers, vertical tail and rear fuselage area of the aircraft. An average difference of 18% in NPR, 12% in
EPR, and 9% in ETR is observed between integrated nozzle and isolated nozzle which further signifies the
importance of integrating exhaust nozzle in aircraft analysis. This proposed methodology will allow more
accurate analysis of the effects of exhaust nozzle on the overall performance of aircraft. The methodology can
further be used for proposing design changes in existing nozzle configurations.
Keywords :
Nozzle Pressure Ratio , Plume , Nozzle , Aerodynamics , Internal Flows
Journal title :
Astroparticle Physics