Study of Two Phase Flow Breakup Behavior for Application to Solid Rocket Motor Nozzle

2014 ◽  
Author(s):  
Ryo S. Amano ◽  
Yi-Hsin Yen ◽  
Michael Hamman
Keyword(s):  
Probability Distribution ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Flow Simulation ◽  
Rocket Motor ◽  
Phase Flow ◽  
Straight Channel ◽  
Solid Rocket Motor ◽  
Two Phase ◽  
Molten Droplets

This paper presents a method of characterizing liquid breakup phenomena using a probability distribution flow pattern and compares CFD results of a straight channel two-phase flow using k-ε, SST k-ω and Reynolds Stress Model (RSM). Examination of liquid breakup level is essential for solving erosion phenomenon of solid fuel rocket motor (SRM), due to their use aluminum based solid propellants. During the propellant combustion, the aluminum oxidizes into alumina (Al2O3), which tends to agglomerate into molten droplets under a certain flow conditions. The molten droplets can then impinge on the combustion chamber walls, and flow along the nozzle wall. Such agglomerated aluminum leads to erosive damages to the geometry of de Laval nozzle and reduces the SRM propulsion performance. The volume fraction (VF) contour of the liquid can be used as the raw data for time average flow VF contour of straight channel. The flow shows the probability distribution of two-phase boundary which is mostly controlled by the features of different turbulence models. Those results will be used for future comparison to two-phase flow experiment as model selection reference of SRM two-phase supersonic flow simulation.

Unsteady Eulerian two-phase flow analysis of solid rocket motor slag

1997 ◽  
Author(s):  
Franck Godfroy ◽  
Jean-Francois Guery ◽  
Franck Godfroy ◽  
Jean-Francois Guery
Keyword(s):  
Two Phase Flow ◽  
Flow Analysis ◽  
Rocket Motor ◽  
Phase Flow ◽  
Solid Rocket Motor ◽  
Two Phase ◽  
Solid Rocket

Gas-Solid Two-Phase Flow Simulation of Coaxial Powder Delivery Nozzle in Rapid Prototyping

2010 ◽  
Vol 29-32 ◽  
pp. 1663-1667 ◽  
Author(s):  
Zhi Jian Wang ◽  
Xiao Feng Shang
Keyword(s):  
Rapid Prototyping ◽  
Metal Powder ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Flow Simulation ◽  
Phase Flow ◽  
Two Phase ◽  
Good Convergence ◽  
And Performance

Coaxial powder delivery nozzle plays an important role in metal part direct and rapid prototyping technology and the reasonable structure can ensure uniform and stable flow of metal powder. Gas-solid two-phase flow theory is considered to simulate outside flow field of carrying gas-type coaxial powder delivery nozzle. The physical and mathematical models are erected. FLUENT software is used to simulate the velocity distribution of gas and solid particle, the volume fraction distribution of particle and the focusing properties. The simulative results indicate that both the structure of coaxial powder delivery nozzle and inlet velocity affect the convergence of powder. When the metal powder is only driven by the carrying gas without the shield gas flow, the powder appears focusing and the focus is 8mm far from the nozzle exit, but the volume fraction at the focus is only 2.6 percent, which shows the convergence of powder is not good and the usage rate is not high. In the optimized structure the simulative results show that the powder flow is affected by the flow of shield gas. When the velocity of shield gas is 6m/s, the powder shows good convergence and the volume fraction of powder at the focus reaches 3.3 percent. The higher the velocity of shield gas is, the more uniformly the powder flows, but the volume fraction at the focus is slightly lower. It is obvious that the numerical simulation will benefit for coaxial nozzle designing and performance improving.

scholarly journals Study on Size Distribution and Flow Characteristics of Condensed Products in Solid Rocket Motor

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mengying Liu ◽  
Zhu Liu ◽  
Shipeng Li ◽  
Wenhao Yu ◽  
Jian Cao ◽  
...  
Keyword(s):  
Size Distribution ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Rocket Motor ◽  
Phase Flow ◽  
Solid Rocket Motor ◽  
Two Phase ◽  
Laser Scattering ◽  
Real Size ◽  
Solid Rocket

The size distribution of condensed products during the combustion of aluminized propellants and flow characteristics of the gas-solid two-phase flow in solid rocket motor were studied in this paper. Firstly, based on the laser scattering technology, an online detection system for condensed products in plume was established, and the size detection of condensed products in the plume of solid rocket motor is carried out. Secondly, a numerical model of two-phase flow in solid rocket motor is established by combining the real size distribution of products in the plume with discrete phase model through the Rosin-Rammler distribution function. Besides, numerical simulation research is carried out under the same experimental conditions, focusing on the influence of condensed products with real size on the characteristics of solid rocket motor. The results show that the innovation measurement system can be used to obtain the size distribution characteristic of condensed products in the plume. At the particle size of stable stage, the mean size, D v 50 , is 104 μm, which is the smallest among all stages. It is also suggested that condensed products at the end stage have the most impact on the flow behavior in solid rocket motor, in that the shock structure, Mach number, and temperature distribution in the near field of plume are significantly changed.

Eulerian Two-Phase Flow Modeling of Steam Direct Contact Condensation for the Fukushima Accident Investigation

2014 ◽  
Author(s):  
Marco Pellegrini ◽  
Giulia Agostinelli ◽  
Hidetoshi Okada ◽  
Masanori Naitoh
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Fluid Model ◽  
Fluid Dynamic ◽  
Interfacial Region ◽  
Phase Flow ◽  
Two Phase ◽  
Fukushima Accident ◽  
Average Cell Size ◽  
Average Cell

Steam condensation is characterized by a relatively large interfacial region between gas and liquid which, in computational fluid dynamic (CFD) analyses, allows the creation of a discretized domain whose average cell size is larger than the interface itself. For this reason generally one fluid model with interface tracking (e.g. volume of fluid method, VOF) is employed for its solution in CFD, since the solution of the interface requires a reasonable amount of cells, reducing the modeling efforts. However, for some particular condensation applications, requiring the computation of long transients or the steam ejected through a large number of holes, one-fluid model becomes computationally too expensive for providing engineering information, and a two-fluid model (i.e. Eulerian two-phase flow) is preferable. Eulerian two-phase flow requires the introduction of closure terms representing the interactions between the two fluids in particular, in the condensation case, drag and heat transfer. Both terms involve the description of the interaction area whose definition is different from the typical one adopted in the boiling analyses. In the present work a simple but effective formulation for the interaction area is given based on the volume fraction gradient and then applied to a validation test case of steam bubbling in various subcooling conditions. It has been shown that this method gives realistic values of bubble detachment time, bubble penetration for the cases of interest in the nuclear application and in the particular application to the Fukushima Daiichi accident.

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