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Results for “CONICAL NOZZLE”

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At least 19 records

Air film cooling in a nonadiabatic wall conical nozzle.

Experimental data for an air-film cooled conical nozzle operating with a heated-air main stream and a water-cooled wall confirm the validity of Lieu's (1964) method for correlating film cooling data in the accelerated flow of a nonadiabatic-wall nozzle. The film cooling effectiveness modified for nonadiabatic walls by Lieu can be used to correlate film cooling under the condition that the main-stream to coolant velocity ratio at the slot is about 1. Such a ratio provides the optimum cooling effectiveness.

Boldman, D. R.

Heat transfer and boundary layer in conical nozzles

A review of a comprehensive experimental investigation of the heat transfer and boundary layer in 30 deg to 15 deg and 60 deg to 15 deg conical nozzles is presented. The experiments were conducted with air at a stagnation temperature of 539 K (970 R) and throat Reynolds numbers based on a diameter ranging from 6 x 10 to the 5th power to 5 x 10 to the 6th power. Nozzle wall surface finish was varied from a smooth machine finish to a 826 x 10 to the minus 6th power cm (325 x 10 to the minus 6th in.) rms sandblasted finish. Measured heat transfer and wall temperatures are tabulated.

Boldman, D. R.

Comparison of acoustic data from a 102 mm conic nozzle as measured in the RAE 24-foot wind tunnel and the NASA Ames 40- by 80-foot wind tunnel

A cooperative program between the Royal Aircraft Establishment (RAE), England, and the NASA Ames Research Center was initiated to compare acoustic measurements made in the RAE 24-foot wind tunnel and in the Ames 40- by 80-foot wind tunnel. The acoustic measurements were made in both facilities using the same 102 mm conical nozzle supplied by the RAE. The nozzle was tested by each organization using its respective jet test rig. The mounting hardware and nozzle exit conditions were matched as closely as possible. The data from each wind tunnel were independently analyzed by the respective organization. The results from these tests show good agreement. In both facilities, interference with acoustic measurement is evident at angles in the forward quadrant.

Atencio, A., Jr.

The Theory of Pulsating Flow in Conical Nozzles

A knowledge of the dynamic characteristics of nozzles and orifices is important in many control and stability analyses of engineering devices. It is usual to assume that the instantaneous flow-rate, for a given set of inlet conditions and outlet pressure, is the same as the nontransient value for the same operating conditions. Recently, in connection with the stability analysis of an externally pressurized thrust bearing, the validity of this assumption was questioned. The analysis presented in this paper was undertaken to provide an answer. The present analysis applies to any fluid, liquid, or gas flowing into a simple conical nozzle. The amplitude and phase of the mass-flux response to a sinusoidally time-varying pressure fluctuation at the nozzle exit are determined. An approximate formula is given for these quantities in terms of the nozzle throat area, the solid angle subtended by the cone, the velocity of the fluid at the nozzle throat, the acoustic velocity at the throat, and the frequency of the pressure fluctuation.

Elrod, H. G., Jr.

Exit of a blast wave from a conical nozzle

The Eulerian computer code DORF was used in the analysis of a two-dimensional, unsteady flow field resulting from semi-confined explosions for propulsive applications. Initially, the ambient gas inside the conical shaped nozzle is set into motion due to the expansion of the explosion product gas, forming a shock wave. When this shock front exits the nozzle, it takes almost a spherical form while a complex interaction between the nozzle and compression and rarefaction waves takes place behind the shock. The results show an excellent agreement with experimental data.

Kim, K.