Effect of altitude is discussed in the unsteady separation of multi stage rockets. Axisymmetric, unsteady and turbulent Navier stokes equations are solved numerically. The governing equations are split into a hyperbolic inviscid part and a parabolic diffusion part. The hyperbolic part is solved by an explicit second-order time and space of Godunov-type scheme. Moving mesh and moving boundary al...

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...

In developing the next generation supersonic transport airplane, two major challenges must be resolved. The fuel efficiency must be significantly improved, and the sonic boom propagating to the ground must be dramatically reduced. Both of these objectives can be achieved by reducing the shockwaves formed in supersonic flight. The Busemann biplane is famous for using favorable shockwave interact...

ABSTRACT The role of relativistic jets in unbinding the stellar envelope during a supernova (SN) associated with gamma-ray burst (GRB) is unclear. To study that, we explore observational signatures explosions that are driven by jets. We focus on final velocity distribution outflow such and compare its imprints to SN/GRB data. find jet-driven produce an flat energy per logarithmic scale proper v...

SUMMARY. An approximate analysis is given of a turbulent wall-jet beneath a stream moving at ocmatant ve1ooity. The results of this analysie are used to predict the drag of a cylindrical afterbody immersed in the jet from a front fan with short oowl at subsonio flight speeds. Graphs are presented tiioh allow rapid evaluation of afterbody drag for a range of jet pressure ratios and nacelle geane...

CONTEXT Quantification of the magnitudes of fluid resistance provided by water jets (currents) and their effect on energy expenditure during aquatic-treadmill walking is lacking in the scientific literature. OBJECTIVE To quantify the effect of water-jet intensity on jet velocity, drag force, and oxygen uptake (VO2) during aquatic-treadmill walking. DESIGN Descriptive and repeated measures. ...

This study concerns numerical simulation, modeling and optimization of aerodynamic stall control using a synthetic jet actuator. Thenumerical simulation was carried out by a large-eddy simulation that employs a RNG-based model as the subgrid-scale model. The flow around a NACA0015 airfoil, including a synthetic jet located at 10 % of the chord, is studied under Reynolds number Re = 12.7 × 106 a...

This work investigates the ability of Coanda jet blowing to modify the base pressure of a cylindrical body aligned axially in a flow, and thereby, produce overall drag reduction. It is found that blowing through one or two slot jets concentric to the outer body circumference can significantly influence the entire base flow region. The recirculating wake is eliminated and is replaced by freestre...

ABSTRACT Many stripped envelope supernovae (SNe) present a signature of high-velocity material responsible for broad absorption lines in the observed spectrum. These include SNe that are associated with long gamma-ray bursts (LGRBs) and low-luminosity GRBs (llGRBs), not GRBs. Recently it was suggested this originates from cocoon is driven by relativistic jet. In LGRBs, jet breaks out successful...

SUMMARY A systematic sex-188 of twin-jet afterbodaes all terminating at the jet-exit has been tested at Mach numbers from M = 0.7 to 1.3 on a strut-mounted rig employing high pressure air for the Jet streams. The afterbody drag was derived from balance measurements of thrust-minus-drag and wind-off calibrations of thrust, and interpreted with the help of pressure plotting data. Two single-nozzl...