INVESTIGATION OF AN AIR-COOLED, PLUG-TYPE, VARIABLE-AREA EXHAUST NOZZLE
Investigation of air-cooled, plug-type, variable- area exhaust nozzle at high temperature
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Investigation of air-cooled, plug-type, variable- area exhaust nozzle at high temperature
Plug nozzle propulsion efficiency
Primary and secondary flow interaction in plug nozzle, obtaining solutions by iteration and isentropic relation
Off-design performance characteristics of two isentropic plug nozzles designed for pressure ratio of 16.5
Aerodynamic shape optimization was performed on an isolated axisymmetric plug nozzle sized for a supersonic business jet. The dual-stream concept was tailored to attenuate nearfield pressure disturbances without compromising nozzle performance. Adjoint-based anisotropic mesh refinement was applied to resolve nearfield compression and expansion features in the baseline viscous grid. Deformed versions of the adapted grid were used for subsequent adjoint-driven shape optimization. For design, a nonlinear gradient-based optimizer was coupled to the discrete adjoint formulation of the Reynolds-averaged Navier- Stokes equations. All nozzle surfaces were parameterized using 3rd order B-spline interpolants and perturbed axisymmetrically via free-form deformation. Geometry deformations were performed using 20 design variables shared between the outer cowl, shroud and centerbody nozzle surfaces. Interior volume grid deformation during design was accomplished using linear elastic mesh morphing. The nozzle optimization was performed at a design cruise speed of Mach 1.6, assuming core and bypass pressure ratios of 6.19 and 3.24, respectively. Ambient flight conditions at design were commensurate with 45,000-ft standard day atmosphere.
Where disconnect pins must be used for wiring and testing a circuit, improved system reliability is obtained by making a permanent joint between pins and sockets of the disconnect plug. After the circuit has been tested, contact points may be fused through soldering, brazing, or welding.
Shear pin coupling with plugged hollow shaft provides required load capacity for shaft protection and has no groove to induce fatigue failure.
Connector which includes a spring-loaded contact to receive a protruding center conductor and an internal collet to clamp against a collar attached to a woven outer conductor, is used as a receptacle for the end of a coaxial cable. This plug-in connector socket is used successfully with remote manipulators.
Expandable metal plug is inserted to provide a seal to support the mold core with small blocks, referred to as chaplets, during the casting of a complex volute. Weld-warpage and multiple X ray inspection are eliminated by use of this technique.
Hand-operated plug insertion valve seals an evacuated insulation system for upper stage liquid hydrogen tanks on the launch pad. It is light in weight, demountable, and permits evacuation of the system plus sealing after evacuation.
Performance evaluation of annular plug and expansion-deflection nozzles including external flow effects at transonic Mach numbers
Aperture-admittance expression for waveguide-fed rectangular aperture antenna, loaded with dielectric plug
Cold flow tests of aerodynamic characteristics of plug nozzle configuration for turbojet engines operating at supersonic speeds
Effects of shroud geometry on performance of collapsible plug nozzle at Mach numbers from 0 to 2.0
Performance of 10 deg conical turbojet plug nozzle with iris primary and translating shroud for supersonic cruise applications
Internal performance data for conical plug nozzle of turbojet gas engine
Static tests of nozzle efficiency and pumping characteristics of conical turbojet plug nozzle with translating primary and secondary shrouds at Mach 0 to 2.0
Waveguide fed rectangular aperture antenna with dielectric plug load, describing admittance resonant perturbation due to excited TE mode