Testing of Parts and Complete Units of the Swedish Base Bleed System

1988 ◽  
Vol 1 (1-6) ◽  
pp. 251-270
Author(s):  
Nils-Erik Gunners ◽  
Kurt Andersson ◽  
Yngve Nilsson
Keyword(s):  
Base Bleed

Ignition and Combustion Behavior of MTV Igniter Materials for Base Bleed Applications

1988 ◽  
Vol 1 (1-6) ◽  
pp. 43-61 ◽  
Author(s):  
B. L. Fetherolf ◽  
D. M. Chen ◽  
T. S. Snyder ◽  
T. A. Litzinger ◽  
Kenneth K. Kuo
Keyword(s):  
Combustion Behavior ◽  
Base Bleed ◽  
Ignition And Combustion

EFFECT OF BASE BLEED DIMENSIONS ON THE BALLISTIC PERFORMANCE OF ARTILLERY PROJECTILES

2014 ◽  
Vol 16 (16) ◽  
pp. 1-24
Author(s):  
H. Abou-Elela ◽  
A. Ibrahim ◽  
O. Mahmoud ◽  
O. Abdel-Hamid
Keyword(s):  
Ballistic Performance ◽  
Base Bleed

Intrinsic features of flow past three square prisms in side-by-side arrangement

2017 ◽  
Vol 826 ◽  
pp. 996-1033 ◽  
Author(s):  
Qinmin Zheng ◽  
Md. Mahbub Alam
Keyword(s):  
Beat Frequency ◽  
Phase Relationship ◽  
Streamwise Velocity ◽  
Viscous Force ◽  
Phase Lag ◽  
Force Coefficient ◽  
Fluid Forces ◽  
Gap Flow ◽  
Base Bleed ◽  
Primary Frequency

An investigation on the flow around three side-by-side square prisms can provide a better understanding of complicated flow physics associated with multiple, closely spaced structures in which more than one gap flow is involved. In this paper, the flow around three side-by-side square prisms at a Reynolds number $Re=150$ is studied systematically at $L/W=1.1{-}9.0$, where $L$ is the prism centre-to-centre spacing and $W$ is the prism width. Five distinct flow structures and their ranges are identified, viz. base-bleed flow ($L/W<1.4$), flip-flopping flow $(1.4<L/W<2.1)$, symmetrically biased beat flow $(2.1<L/W<2.6)$, non-biased beat flow $(2.6<L/W<7.25)$ and weak interaction flow $(7.25<L/W<9.0)$. Physical aspects of each flow regime, such as vortex structures, vortex dynamics, gap-flow behaviours, shedding frequencies and fluid forces, are discussed in detail. A secondary (beat) frequency other than the Strouhal frequency (primary frequency) is observed in the symmetrically biased and non-biased beat flows, associated with the beat-like modulation in $C_{L}$-peak or amplitude, where $C_{L}$ is the lift force coefficient. Here we reveal the generic and intrinsic origin of the secondary frequency, establishing its connections with the phase lag between the two shear-layer sheddings from the two sides of a gap. When the two sheddings are in phase, no viscous force acts at the interface (i.e. at the centreline of the gap) of the two sheddings, resulting in the largest fluctuations in streamwise momentum, streamwise velocity and pressure; the maximum $C_{L}$ amplitude thus features the in-phase shedding. Conversely, when the two sheddings are antiphase, a viscous force exists at the interface of the two sheddings and restricts the momentum fluctuation through the gap, yielding a minimum $C_{L}$ amplitude. When the phase relationship between the two sheddings changes from in phase to antiphase, the extra viscous force acting at the interface becomes larger and causes the $C_{L}$ amplitude to change from a maximum to a minimum.

Propelling Nozzle Research

1964 ◽  
Vol 68 (647) ◽  
pp. 717-727 ◽  
Author(s):  
W. G. E. Lewis
Keyword(s):  
High Speed ◽  
High Performance ◽  
Research Programme ◽  
Static Tests ◽  
Transport Aircraft ◽  
Supersonic Transport ◽  
Design Behaviour ◽  
Base Bleed ◽  
Critical Phases ◽  
The Ideal

SummaryThe current interest in supersonic transport aircraft makes it appropriate to consider the problems of propulsion nozzle systems for high speed flight. The discussion will be confined mainly to this field of activity.In the absence of external drag and weight factors, the ideal configuration to maintain optimum thrust at all flight speeds would employ a mechanically variable area ratio nozzle. By such means the jet flow could be fully and properly expanded at all times.A practical design to accommodate such variations is inherently complex, and so an alternative solution using aerodynamic techniques has been sought. It is necessary to remember that the success of whatever method is eventually chosen must rest on its ability to combine a high performance at cruise with very small loss during other critical phases of the flight plan.This paper describes some of the results of a nozzle research programme aimed primarily at solving the above problem, with an attempt to explain the philosophy behind the aerodynamic techniques tried. Some discussion is given of the experimental difficulties in establishing a sufficiently accurate standard of measurement for design point performance. In a few chosen configurations experimental results have been extensively backed by theoretical studies.The need to demonstrate off-design behaviour in the presence of an external flow field is stressed, with special reference to the misleading results often obtained from static tests.Finally, some attention is given to the question of base bleed, with its repercussions on the installation of the propulsion nozzle in an aircraft.

Burning rate of AP/HTPB base-bleed composite propellant under free ambient pressure

2017 ◽  
Vol 62 ◽  
pp. 31-35 ◽  
Author(s):  
Lingke Zhang ◽  
Ruyuan Tian ◽  
Zhuwei Zhang
Keyword(s):  
Burning Rate ◽  
Ambient Pressure ◽  
Composite Propellant ◽  
Base Bleed

An experimental study of geometries for base bleed

1996 ◽  
Author(s):  
I. Bowman ◽  
J. Edwards
Keyword(s):  
Experimental Study ◽  
Base Bleed
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