Approximate Solution of Isentropic Swirling Flow Through a Nozzle

Mager, Artur

doi:10.2514/8.5732

Cited by 48 publications

(16 citation statements)

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“…The analysis of swirling nozzle flows has attracted the interest of several investigators, the contributions of which are cited as [2][3][4][5][6][7][8][9][10][11]. The present analysis differs from the prior work not only in method of solution, but also in basic formulation in that the present solutions are initiated from given information at the nozzle throat.…”

Section: Introductioncontrasting

confidence: 42%

Compressible swirling flow through convergent-divergent nozzles

Boerner

Sparrow

Scott

1972

Wärme- und Stoffübertragung

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The effects of swirl on the rate of mass flow and on the velocity field in the throat region of axi-symmetric nozzles are studied analytically and experimentally, tn the analytical phase, methods are developed for treating either the direct or the inverse problem for flow in de Laval and annular nozzles, taking account of either weak or strong swirl. The experiments were performed in an annular nozzle, with swirl being imparted to the flow by adjustable vanes situated upstream of the test section.The analytical results facilitated an examination of the effects of swirl strength, distribution of swirl, and nozzle geometry. The rate of mass flow was found to decrease with increasing swirl strength. The mass flow results were well correlated by a swirl strength parameter evaluated at the throat, with swirl type and geometry being of secondary importance. Another effect of swirl was to shift the sonic line upstream of the geometric nozzle throat. The experimentally determined mass flow results were in agreement with the analytical predictions. Also, all of the qualitative characteristics of the local flow field measurements were reproduced by the analytical results. Nomendamre

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Section: Introductioncontrasting

confidence: 42%

Compressible swirling flow through convergent-divergent nozzles

Boerner

Sparrow

Scott

1972

Wärme- und Stoffübertragung

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“…Several authors have investigated this subject and developed some analytical solutions [ [22][23][24][25]. Those models have been used in this work to estimate the effect of the swirling flow on the nozzle discharge coefficient.…”

Section: Efficiencymentioning

confidence: 99%

Numerical and Experimental Investigation of Unidirectional Vortex Injection in Hybrid Rocket Engines

Bellomo

Barato

Faenza

et al. 2013

Journal of Propulsion and Power

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A study on vortex injection in hybrid rocket engines with nitrous oxide and paraffin has been performed. The investigation followed two paths: first, the flowfield was simulated with a commercial computational fluid dynamics code; then, burn tests were performed on a laboratory-scale rocket. The computational fluid dynamics analysis had the dual purpose to help the design of the laboratory motor and to understand the physics underlying the vortex flow coupled with the combustion process compared with axial injection. Vortex injection produces a more diffuse flame in the combustion chamber and improves the mixing process of the reactants, both aspects concurring to increase the c efficiency. A helical streamline develops downstream of the injection region, and the pitch is highly influenced by combustion, which straightens the flow due to the acceleration in the axial direction imposed by the temperature rise. Experimental tests with similar geometry have been performed. Measured performance shows an increase in regression rate up to 51% and a c efficiency that rises from less than 80% with axial injection up to more than 90% with vortex injection. Moreover, a reduction of the instabilities in the chamber pressure has been measured. Nomenclature A t= nozzle throat area a = multiplication coefficient for regression rate G ox = mass flux in combustion chamber L g = grain length M f = mass of burned fuel M m = molar mass _ m tot = mean total mass flow n = exponential coefficient for regression rate O∕F = oxidizer to fuel mass ratio p, pc = pressure, mean chamber pressure R u = universal gas constant r = radial coordinate T = temperature t = time u r , u z , u θ = radial, tangential, and axial velocity z = axial coordinate μ = dynamic viscosity ρ f = density of fuel ρ = density ϕ i , ϕ e , ϕ m = initial, final, and mean diameter of the grain ω = vortex angular velocity

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“…In the case of a single vortex (first traveling tangential mode), the effective area of the nozzle throat is reduced seriously, 6 and large increases in chamber pressure may occur. At the higher pressure, the combustion is usually stable, and this mode appears to be self-annihilating, surviving only about 0.1 sec for the configuration used.…”

Section: Effects Produced By Vorticesmentioning

confidence: 99%