Improvements of the base bleed effect using reactive particles

Bournot, Hervé; Daniel, Éric; Cayzac, Roxan

doi:10.1016/j.ijthermalsci.2006.01.018

Cited by 20 publications

(9 citation statements)

References 26 publications

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“…For the injection mass flow rate, the dimensionless injection parameter I is generally used. It defined as the bleed mass flow rate normalized by the product of the base area and the free stream mass flux [11].…”

Section: Base Bleedmentioning

confidence: 99%

Experimental Aerodynamic Characteristics of Flapping Membrane Wings

Zakaria

Bayoumy

Elshabka

et al. 2009

International Conference on Aerospace Sciences and Aviation Tec

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A computational investigation for the 155mm artillery shell was conducted for the purpose of reducing the base drag. Three case studies were conducted to investigate the properties of the flow field around the shell for the flight at different Mach numbers at zero angle of attack. The three cases were: a shell with boattail, a shell with base cavity and a shell with base bleed. Also, combinations of these three cases were investigated. The higher drag reduction was demonstrated when using a combination of the three effects. For this latter case it was possible to realize a drag coefficient reduction of ~60% at subsonic regime and ~20-30% .at transonic and supersonic regimes. Based on the present methodology, a design optimization for minimum drag can be applied on similar flying bodies.

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Section: Base Bleedmentioning

confidence: 99%

Experimental Aerodynamic Characteristics of Flapping Membrane Wings

Zakaria

Bayoumy

Elshabka

et al. 2009

International Conference on Aerospace Sciences and Aviation Tec

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“…Lee et al [24] performed a similar RANS study while using the standard k-ω turbulence model in the Fluent solver. Bournot et al [25] performed a numerical study of the base bleed and showed that the introduction of reactive particles in the subsonic bleeder jet may improve effectiveness by leading to higher pressure on the base surface. Shin and Choi [26] obtained good agreement with the experimental results when they performed DDES (Delayed Detached Eddy Simulation) study of the supersonic base flow and effect of the base bleed technique.…”

Section: Introductionmentioning

confidence: 99%

Numerical study of flow physics in supersonic base-flow with mass bleed

Das

2016

Aerospace Science and Technology

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Large Eddy Simulation (LES) with dynamic sub-grid scale eddy viscosity model has been applied to numerically investigate the evolution of complicated flow structures in supersonic base flow with mass bleed. Mean flow properties obtained from numerical simulations, such as axial velocity, pressure on the base surface, have been compared with the experimental measurements to show that LES is able to predict the mean flow properties with acceptable accuracy. The data obtained from LES has been further analyzed to understand the evolution of coherent structures in the flow field. Periodical shedding of vortical structures from the outer shear layer has been observed and it has also been found that this vortex shedding is associated with the flapping of the outer shear layer. The frequency of flapping of the outer shear layer has been found out and the phase-averaged streamlines have been analyzed to further study the evolution of vortical structures associated with this flapping. The phase-averaged streamline plots clearly elucidate the evolution of vortical structures along the outer shear layer. Further, the study of these structures is investigated by performing Proper Orthogonal Decomposition (POD) analysis of the data, obtained along the central plane in the wake region. The POD results also 2 seem to agree well with the observations made in the phase averaged streamline plots, as the concentrated energy and enstropy are observed in the outer shear layer with fewer POD modes.

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“…Based on the value of mass flow rate of the bleeded gases [5] as shown in Figure ( Base pressure versus injected mass flow rate [5] S. Jaramaz et. al [7] introduced mathematical model that calculates the ballistic performance of base bleed grain.…”

Section: Introductionmentioning

confidence: 99%

The Optimization of Base Bleed Grain Parameters for Maximum Ballistic Performance

Abou-Elela

Ossama

Ibrahim

et al. 2015

International Conference on Aerospace Sciences and Aviation Tec

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Solid propellant Base bleed unit is one of the effective methods to increase the range of artillery projectiles. As far as we search, no published study focuses on the optimal dimensions of the base bleed grain. However, few studies focus on the effect of base bleed grain parameters on its ballistic performance in which each parameter was studied separately. The present optimization study is performed on base bleed grain which performed as longitudinally slotted tubular cylinder. Different case studies have been introduced according to the number of design variables which are: grain outer, inner radius, length, burn rate, base bleed grain unit orifice diameter. Moreover, the study is extended to demonstrate the effect of these parameters on the innovative multi-burn rate base bleed grain. In this new idea, the grain is splitted into two horizontal parts one with higher burn rate than the other part. The idea is to have a grain that provides high mass flow rate in the first seconds of projectile flight, while keeping long bleeding time. The optimization constrains are the upper and lower limits of each design variable. An analytical model has been developed in C++ environment to accurately evaluate the range of the projectile. This model is then utilized in combination with design of experiment (DOE) and the response surface method (RSM) to develop a smooth response function which can be effectively used in the design optimization formulation as the objective function. The objective of the optimization is to find the design variables which contribute the maximum range. Paper: ASAT-16-171-AE The results show the importance of applying optimization and provided the optimized values of the studied parameters at each case. Also it shows that the application of the new idea of multi-burn rate base bleed increases the range in all cases with percentage up to 12 % with respect to the range increase for the original base bleed grain.

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Improvements of the base bleed effect using reactive particles

Cited by 20 publications

References 26 publications

Experimental Aerodynamic Characteristics of Flapping Membrane Wings

Experimental Aerodynamic Characteristics of Flapping Membrane Wings

Numerical study of flow physics in supersonic base-flow with mass bleed

The Optimization of Base Bleed Grain Parameters for Maximum Ballistic Performance

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