Aerodynamic performance evaluation of twinjet afterbody using flow through balance
نویسندگان
چکیده
To understand / evaluate behaviour of these complex jets freestream interactions, experiments were carried out in the freestream Mach number range of 0.6 to 1.8 varying jet pressure ratios in the range of 1 to about 15 on a twin jet afterbody configuration. Test results show that afterbody total drag in general increased (for the Mach number range of this investigation) with the increase in jet pressure ratios due to the entrainment effect of the twin supersonic nozzle jets flow for this afterbody configuration. Oil flow visualization studies also show the intense effect of twin jets freestream interactions at transonic speeds as is indicated by large separated flow regions in and around the base region / nozzles external surface, resulting in relatively a higher transonic drag.
منابع مشابه
Turbulence Modeling Validation for Afterbody Flows
The aerothermodynamics phenomena over space launch vehicles or missiles are a challenging problem on space and aeronautical applications. These physical phenomena can strongly affect the engine's aerodynamic performances. The physical problem met on this geometry is essentially the result of the interaction of two merging flows; one issued from a propulsive jet at high speed and high temperatur...
متن کاملThe Effects of Changes in Height on the Aerodynamic Performance of Automobiles
In this study, the fluid flow around a Pride vehicle was solved in a two-dimensional design using numerical methods. To do so, a two-dimensional figure of a Pride was modeled and gridded, and different surfaces were introduced. Then, governing equations the fluid flow was solved for the standard K-ε model and the appropriate boundary conditions. Areas that increased lift and drag forces...
متن کاملAerodynamic Design Optimization Using Genetic Algorithm (RESEARCH NOTE)
An efficient formulation for the robust shape optimization of aerodynamic objects is introduced in this paper. The formulation has three essential features. First, an Euler solver based on a second-order Godunov scheme is used for the flow calculations. Second, a genetic algorithm with binary number encoding is implemented for the optimization procedure. The third ingredient of the procedure is...
متن کاملSound Radiation from a Lined Exhaust Duct with Lined Afterbody
AFT fan noise radiating from the bypass exhaust duct is usually attenuated by acoustic lining along the inside of the duct only. The unconventional treatment of the afterbody, recently proposed by Tester et al. [1–3] has been shown to provide an additional potential of damping of the order of 1 to 4 dB. This is remarkable, given the fact that most of the sound is supposed to radiate away from, ...
متن کاملMinistry of Technology
This is an experimental comparison Of two axi-symmetric, isentropic plug nozzles. In one of these (Model No. 1) the afterbody is cylindricaland a secondary flow is bled into the annular base. The other (Model No. 2) has a parabolic afterbody with no base or bleed. In both cases the expansion is all-external and the design pressure ratio is 14. These models were tested over a range of primary an...
متن کامل