Ballistic Analysis of a Projectile Provided with Base Bleed Unit

Abou-Elela, H.; Ibrahim, A. Z.; Mahmoud, O. K.; Abdelhamid, O. E.

doi:10.21608/asat.2013.22270

Cited by 4 publications

(20 citation statements)

References 10 publications

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“…In this study, the effect of the main dimensions of base bleed grain is discussed through an analytical model which its predictions were previously verified [17]. These dimensions are the length, inner diameter and maximum diameter.…”

Section: Introductionmentioning

confidence: 79%

“…Experimental work showed that the optimum injection parameter for base bleed projectile is approximately 0.005 [23]. The injection parameter is calculated according to the following equation [17]:…”

Section: Governing Equations Of Flow Rates and Flow Regimesmentioning

confidence: 99%

“…Ejected gases from the base bleed unit are responsible for the base drag reduction resulting in range extension of artillery projectiles. Base bleed effect has been studied by many researchers using different approaches such as firing tests [1][2][3][4][5], wind tunnel experiments [6][7][8][9], analytical methods [10][11][12][13][14][15][16][17] and computational fluid dynamic simulations [18][19][20][21]. In some of these studies, the researchers used solid propellants as the source of the ejected gases.…”

Section: Introductionmentioning

confidence: 99%

“…It has been proven in Ref. [17] that base drag reduction -via base bleeding -at high supersonic velocities of artillery projectiles is more efficient.…”

Section: Introductionmentioning

confidence: 99%

“…Base bleed grain consists of two identical solid propellant grains as shown in Fig. 1 [17]. The surfaces exposed to burning are an inner cylinder and four flat surfaces; each pair is separated by a slot (ω i ) of 3 mm.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effect of Base Bleed Dimensions on the Ballistic Performance of Artillery Projectiles

Abou-Elela

Ibrahim

Mahmoud

et al. 2014

The International Conference on Applied Mechanics and Mechanica

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Base bleed unit is one of the active methods to increase the range of artillery projectiles. Ballistic performance of base bleed unit has been experimentally assessed using firing tests and wind tunnel experiments. Meanwhile, analytical and numerical studies have been carried out. In some of these studies, solid propellant is used as the source of the burnt gases ejected into the wake behind the projectile base. But, in other studies, different types of gases such as air, argon, hydrogen, and helium are ejected at different temperatures. In this paper, the effects of the main dimensions of 2-parts tubular base bleed grain unit on its ballistic performance are studied analytically. These dimensions are base bleed grain maximum radius, length, inner diameter of the grain, and exit diameter of base bleed unit. The study is applied to the base bleed unit which is installed to K307 155mm projectile. The study leads to a new method to control the ejected mass flow rate. This method is based on changing the exit diameter of base bleed unit in order to get higher injection parameter in the first few seconds of projectile flight and lower values in the remaining time of base bleed grain burning. Therefore, the base bleed projectile range is increased by 1.7 % when comparing with its counterpart which is supplied with base bleed unit having constant exit diameter and the same base bleed grain.

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Section: Introductionmentioning

confidence: 79%

Section: Governing Equations Of Flow Rates and Flow Regimesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…It has been proven in Ref. [17] that base drag reduction -via base bleeding -at high supersonic velocities of artillery projectiles is more efficient.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Base Bleed Dimensions on the Ballistic Performance of Artillery Projectiles

Abou-Elela

Ibrahim

Mahmoud

et al. 2014

The International Conference on Applied Mechanics and Mechanica

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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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Design and Analysis of a Base Bleed Unit for the Drag Reduction of a High-Power Rocket Operating at Transonic Speeds

Famellos,

Skevas,

Koutsiadis

et al. 2024

Aerospace

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In the present study, a passive flow device is considered for drag reduction purposes through implementation in a transonic high-power rocket. The high-power rocket serves as a reference platform that, apart from the operating conditions, enforces several constraints in terms of available volume and placement locations. A step-by-step methodology is suggested, where the unit is initially broken down into an inlet and an outlet component. The flow field is investigated by means of computational modeling (CFD), where the Reynolds-averaged Navier–Stokes equations are solved coupled with turbulence models that vary depending on the design phase and the individual component. In the first design phase, the best alternative configuration is selected for each component by comparing mass flow rates and discharge coefficients. In the second design phase, each component is analyzed in greater detail based on the first phase results. Indicatively, the protruding inlet diffuser-type channel is converted into a protruding inlet nozzle-type channel to avoid choked flow phenomena, and a nozzle geometry is selected as the outlet amongst the other considered scenarios. The two components are eventually integrated into a common base bleed unit and a final assessment is made. The computational results are used to predict the performance and trajectory of the rocket through a well-established trajectory software. The overall methodology is validated against full-scale test flight data. The results show that the base bleed unit developed in the framework of this study yields a drag reduction of approximately 15% at transonic speeds without impacting the rocket mass and stability.

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Ballistic Analysis of a Projectile Provided with Base Bleed Unit

Cited by 4 publications

References 10 publications

Effect of Base Bleed Dimensions on the Ballistic Performance of Artillery Projectiles

Effect of Base Bleed Dimensions on the Ballistic Performance of Artillery Projectiles

The Optimization of Base Bleed Grain Parameters for Maximum Ballistic Performance

Design and Analysis of a Base Bleed Unit for the Drag Reduction of a High-Power Rocket Operating at Transonic Speeds

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