Experimental study of rheological properties of solid propellant slurry at low‐shear rate and numerical simulation

2020 ◽  
Vol 137 (42) ◽  
pp. 49287
Author(s):  
Yue Wu ◽  
Zhuo Li ◽  
Yong‐chao Ji ◽  
Rong Lu
2013 ◽  
Vol 739 ◽  
pp. 117-122
Author(s):  
Hojjatollah Sadeghipour ◽  
Farshid Ghorbani ◽  
Mohammad Reza Jafari Felavarjani ◽  
Hassan Ebadi-Dehaghani ◽  
Davoud Ashouri ◽  
...  

The effect of several types of nanoparticles on the rheological properties of polycarbonate (PC) was compared. Four polycarbonate nanocomposites containing 5 wt% of layered silica (SiO2), Iron oxide (Fe3O4), Iron oxide (α-Fe2O3), cupric oxide (CuO) nanoparticles were prepared via melt compounding at 260 °C. Compression molded samples were prepared and the dynamic rheological properties of the nanocomposites were investigated. The incorporation of the nanoparticles increased the storage modulus and consequently decreased the damping factor. In the Cole-Cole plot, PC filled layered silica and Fe2O3 nanoparticles showed more semi-circle pattern comparing to that of other nanocomposites implied more compatibility between PC and layered silica and also Fe2O3 nanofillers. While other nanocomposites showed more deviation from this pattern. Rotational mode in rheological studies showed that at low shear rate the viscosities of nanocomposites are higher than that of pure Polycarbonate. While at higher shear rate the viscosity of filled samples tend to approach the viscosity of pure PC.


Polimery ◽  
2008 ◽  
Vol 53 (07/08) ◽  
pp. 507-512 ◽  
Author(s):  
BERENIKA HAUSNEROVA ◽  
NATALIE HONKOVA ◽  
ANEZKA LENGALOVA ◽  
TAKESHI KITANO ◽  
PETR SAHA

2014 ◽  
Vol 217-218 ◽  
pp. 144-150
Author(s):  
Xiao Gang Hu ◽  
Fan Zhang ◽  
You Feng He ◽  
Stephen Midson ◽  
Qiang Zhu

Blistering is one of the main surface defects of thixocasting parts after solution treatment. In this paper, experimental study about the influence of plunger velocity on blistering problem was carried out, and the blistering level with various velocities was discussed. In addition, a series of simulation work for filling process were performed to analyse the formation mechanism of blister. The results indicate that the power law cut-off model can reflect the thixotropic characteristics better at shear rate range from 100s-1to 500s-1than Carreau model. Based on power law cut-off (PLCO) model, the filling process simulation reveals the air entrapments were caused by poor venting instead of turbulence, either decreasing the filling speed or modification of the die venting system would improve blistering problem.


2006 ◽  
Vol 953 ◽  
Author(s):  
Sameer Sharad Rahatekar ◽  
Jeffrey W Gilman ◽  
K K Koziol ◽  
Simon Butler ◽  
James A Elliott ◽  
...  

ABSTRACTIn this pape effect of nanotube aggrates on the rheological properties of multiwall carbonanntube abd epoxy suspension in epoxy resin.The base epoxy resin was found to be essentially Newtonian, and the progressive incorporation of nanotubes enhanced the low shear rate viscosity of the suspension by nearly two decades. At higher shear rates, the suspension viscosity asymptotically thinned to the viscosity of the matrix alone. The low shear rate viscosity enhancement was correlated with the optical observations of interconnected aggregates of carbon nanotubes, which themselves were induced by the low shear conditions. Intermediate shear rates resulted in a reduction in the size of the aggregates. High shear rates appeared to cause near complete dispersal of the aggregates. From these results it is conjectured that for this suspension, shear thinning is connected with the breaking of the interconnected network between aggregates of nanotubes, and not by nanotube alignment.


2014 ◽  
Vol 660 ◽  
pp. 244-248
Author(s):  
Mohd Suffian Misaran ◽  
Rossalam Sarbatly ◽  
Md Mizanur Rahman

In the present work, the rheological properties in terms of shear stress and viscosity of Kaolin/Polyether-Sulfone (PESf) of varying ratio were investigated by a rotating rheometer. The shear rate of Kaolin/PESf sample was measured at increasing interval shear rate. By assuming that the fluid behaves like a typical Non-newtonian polymeric liquid, the consistency index, K and flow index, n were able to be determined. Thus, the rheology behaviors of the kaolin/PESf suspension could be investigated at a wider range of shear rate. The shear stress was found to increase with increasing shear rate, with the rate of change quite apparent at low shear rate. At higher shear rate, the shear stress increases definitively with the increase of kaolin content. On the other hand, the viscosity decreased at a faster rate initially and slows down to monotonous rate as the shear rate increases. Evidently at increasing shear rate, the viscosity tends to become constant as the deviation become smaller which is also known as zero shear rate viscosity region.


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