A Predictive Numerical Model of the Burning Rate of Pb 3 O 4 −Si Delay Composition

2019 ◽  
Vol 44 (5) ◽  
pp. 623-629
Author(s):  
Han Zhang ◽  
Shang‐Hao Liu ◽  
Chi‐Min Shu
Keyword(s):  
Numerical Model ◽  
Burning Rate ◽  
Delay Composition

Effects of the Binders on the Storage Stability of the Silicon Delay Composition

2014 ◽  
Vol 977 ◽  
pp. 135-140 ◽  
Author(s):  
Ti Fei Han ◽  
Shi Long Yan
Keyword(s):  
Burning Rate ◽  
Heat Sink ◽  
Storage Stability ◽  
Storage Conditions ◽  
Mixing Process ◽  
Basic Formula ◽  
Temperature And Humidity ◽  
Delay Composition ◽  
Variation Rule

To study effects of binders on storage stability of the silicon delay composition, sample B and C1 were prepared separately by adding shellac and fluororubber(FPM2602) in basic formula A, and sample C2 and C3 were prepared by changing adding amounts and modes of fluororubber respectively. On conditions of 71°C and 92% humidity variation rule of burning rate and delay precision varying with time was studied. The results indicate that binders have function of “heat sink”, and reduce burning rate and delay precision of the delay composition, especially the effects of shellac are obvious. Under two kinds of storage conditions, sample B adding with shellac can obviously improve agents influenced by temperature and humidity. Increasing fluororubber contents the delay composition can also be improved influenced by temperature and humidity. Binders at constant amounts, fluororubber solution in adding directly to the composition in mixing process can improve the delay precision.

CNTs Mixed into W and B by Ball-Milling Method and their Application in Delay Composition

2014 ◽  
Vol 924 ◽  
pp. 343-348 ◽  
Author(s):  
Si Yi Wang ◽  
Hui Ren ◽  
Qing Jie Jiao ◽  
Bao Liang Han
Keyword(s):  
Burning Rate ◽  
Ball Milling ◽  
Size Structure ◽  
High Heat ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Transmission Electron ◽  
Milling Method ◽  
Delay Composition ◽  
The Stability

With the progress in science and technology, the dynamic security, the reliability, the accuracy and the stability of delay composition in complicated condition attracts more and more attentions. Traditional delay composition can not meet our requirements of the reliability and security. Its the first time carbon nanotubes (CNTs) with high heat conductivity and high intensity are added into the system of Tungsten type delay composition and boron type delay composition. CNTs were mixed into W and B by ball-milling method. Particle size analysis and transmission electron microscopy (TEM) are utilized to analyse the size structure and dispersity of W/ CNTs and B/ CNTs. Optimum conditions of preparing W/CNTs and B/CNTs were found to apply to fuel agent of delay composition. In addition, burning rate and delay precision of the four delay charges (BaCrO4/W, BaCrO4/W/CNTs,BaCrO4/B and BaCrO4/B/CNTs delay compositions) were reseached. Results show that delay compositions added to CNTs had higher burning rate and better delay precision than original delay charges (burning rate of BaCrO4/W/CNTs was as much as 3-4 times higher than that of BaCrO4/W under the same constraints. Meanwhile, burning rate of BaCrO4/B/CNTs is 2 times higher than that of BaCrO4/B). Especially, the ignition reliability of charges added to CNTs were improved while charge density exceeds about 6000 Kg/m3. So the addition of certain amount of CNTs in the delay compositions can obviously increase the burning rate and the ignition reliability of delay compositions.

scholarly journals Development and Experimental Investigation on Delay Time Consistency of Modified Si/PbO/Pb3O4/FG Pyrotechnic Delay Composition

2017 ◽  
Vol 7 (6) ◽  
pp. 2167-2170
Author(s):  
Α. Khan ◽  
Z. H. Lodhi ◽  
A. Q. Malik
Keyword(s):  
Experimental Investigation ◽  
Burning Rate ◽  
Delay Time ◽  
Critical Parameter ◽  
Time Consistency ◽  
Pyrotechnic Composition ◽  
Delay Composition ◽  
Time Accuracy

In the present study, experimental investigation was carried out on the delay time consistency of modified Si/PbO/Pb3O4/FG pyrotechnic delay composition in a delay tube. Where Si is the fuel, PbO/Pb3O4 are oxidizers and Fish Glue (FG) is the binder. Ingredient mixing and loading pressure were studied. Results revealed that homogenous mixing of the delay composition is a very critical parameter for controlling the time consistency of pyrotechnic delay composition. The delay time accuracy was improved from 25% to about 7.42% by ensuring homogenous mixing of the ingredients. Results also show that loading pressure ranged from 30,000 to 65,000 psi did not affect much the delay time of this pyrotechnic composition and the burning rate.

NUMERICAL MODEL TO SIMULATE THE EROSION ON THE SLOPE DUE TO OVERTOPPING

2010 ◽  
Vol 13 (3) ◽  
pp. 78-87
Author(s):  
Hoai Cong Huynh
Keyword(s):  
Numerical Model ◽  
Flow Model ◽  
Bed Load ◽  
Experiment Data ◽  
Step Method ◽  
Morphological Model ◽  
Load Transport ◽  
Bed Load Transport ◽  
The Finite Difference Method ◽  
Good Agreement

The numerical model is developed consisting of a 1D flow model and the morphological model to simulate the erosion due to the water overtopping. The step method is applied to solve the water surface on the slope and the finite difference method of the modified Lax Scheme is applied for bed change equation. The Meyer-Peter and Muller formulae is used to determine the bed load transport rate. The model is calibrated and verified based on the data in experiment. It is found that the computed results and experiment data are good agreement.

A numerical model to verify the communication between Gari and Peccia springs (Cassino, Central Italy)

2015 ◽  
Vol 35 ◽  
pp. 268-271
Author(s):  
Michele Saroli ◽  
Michele Lancia ◽  
Marco Petitta ◽  
Gabriele Scarascia Mugnozza
Keyword(s):  
Numerical Model ◽  
Central Italy
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