Wyniki wyszukiwania - BazTech

1

The Flow and Heat Transfer Behavior of Liquid COMP-B3 in Slow Cook-off

Zhou Jie, Wang Shuai, Liu Zide, Zhang Haiyan, Pi Aiguo

Central European Journal of Energetic Materials

|

2023

|

Vol. 20, no. 3

340--363

EN

In order to investigate the flow and heat transfer characteristics of COMP-B3 under thermal stimulation, a series of slow cook-off experiments were designed and conducted, encompassing different sample sizes and heating conditions. The internal temperature profiles were captured using a high-speed data acquisition system. Subsequently, the internal flow and heat transfer conditions of the liquid COMP-B3 were analyzed through numerical simulations employing a non-Newtonian flow model. The results demonstrated the presence of heat convection within the liquid COMP-B3, regardless of sample sizes or heating conditions. However, it should be noted that the occurrence of heat convection is not necessarily observed at the onset of melting. The overall cook-off process can be categorized into three phases: solid (with melting), thermal conduction, and thermal convection. If convection occurs prior to the self-heating reaction, the direction of the flow field within the liquid COMP-B3 experiences a reversal near ignition. Additionally, a predictive method for the flow behaviour inside the liquid COMP-B3 during slow cook-off is proposed. Rough estimates of the flow conditions can be made based on the charge temperature, the internal temperature difference, and the characteristic length. Importantly, these phenomena are theoretically applicable to a wide range of mixed melt-cast explosives, extending beyond COMP-B3. The results provide additional reference value for further investigations into the ignition characteristics of mixed melt-cast explosives under thermal stimulation.

2

Dynamic Processes Modeling in a Peristaltic Pump with a Hydraulic Drive for the Bingham Fluid

Shatokhin Vladimir M., Ivanchuk Yaroslav V., Dvirna Olha, Veselovskaya Natalia, Jurczak Wojciech

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 4

256--269

EN

At present peristaltic pumps are widely used in many branches of industry and national economy. Simplicity of construction, processability and possibility of pumping liquids with big quantity of solid particles are the main advantages while using peristaltic pumps. Therefore development of methods of rational choice of parameters at designing of peristaltic pumps is the actual problem. To develop universal mathematical models of dynamic processes in peristaltic pumps for definition of rational technical parameters. In dynamic processes we propose to use differential equations of motion in the Lagrange form, where the angle of rotation of the pump rotor is taken as a universal coordinate. Mathematical model of dynamic processes in peristaltic pump with hydraulic drive has been created on the base of differential equation. The function of resistance forces caused by gravity forces of mixture particles in the hose reel has been determined. On the basis of the non-linear model of the resistance forces to the flow of the fluid Bingham method of constructing the dependence of the pressure drop on the angular velocity of the rotor to determine the resistance forces to the flow of the fluid has been proposed. The result of dynamic processes simulation is the determination of interrelationship of technological parameters of the device functioning: the velocity of the medium and pump performance is increasing at reducing the length of the diverting hose and reducing the height of its rise; a significant influence on the average speed has plastic viscosity of the environment; a significant change in the yield strength has an insignificant impact on the speed.

3

A two-layered blood flow model of Bingham type non-Newtonian fluid

Das K., Jana S.

International Journal of Applied Mechanics and Engineering

|

2012

|

Vol. 17, no. 1

17-26

EN

In the present paper, a two layered blood flow model through a cylindrical tube of a Bingham type non-Newtonian fluid is considered. The relative coefficients of viscosity for peripheral and core layer are determined and their nature is shown graphically for different values of the maximum hematocrit, shape parameter, etc.

4

Badania współczynnika strat miejscowych podczas przepływu zawiesiny lodowej przez nagłe zwężenie rury

Mika Ł.

Inżynieria i Aparatura Chemiczna

|

2010

|

Nr 1

73-74

PL

W pracy przedstawiono oryginalne wyniki badań doświadczalnych współczynnika strat miejscowych dla zawiesiny lodowej, o udziałach drobinek lodu 5-30%, podczas przepływu przez kilka rodzajów nagłych zwężeń rury w odniesieniu do wyników obliczeń teoretycznych. W pracy wskazano także zalecane i niezalecane zakresy liczby Reynoldsa dla przepływu zawiesiny przez nagłe zwężenia rury. W pracy pokazano także zakresy przepływu, w których wartość współczynnika strat miejscowych zależy od liczby Reynoldsa.

EN

The experimental results of resistance coefficient measurements were presented in the paper. Investigations were carried out with slurry ice flow (concentration of 5-30%) in several kinds of pipe sudden contractions. The experimental and theoretical results were compared. The recommended and not recommended Reynolds number of slurry ice flow in pipe sudden contractions based on experimental results were presented. It was shown that the flow zone defined by resistance coefficient depends on the Reynolds number.

5

MHD flow and heat transfer of a Bingham fluid in an eccentric annulus with the Hall effect

Sayed-Ahmed M. E., Attia H. A.

Computer Assisted Mechanics and Engineering Sciences

|

2007

|

Vol. 14, No. 1

25-42

EN

The steady laminar flow and heat transfer of an incompressible, electrically conducting, non-Newtonian Bingham fluid in an eccentric annulus are studied in the presence of an external uniform magnetic field. The inner cylinder is subject to a constant heat flux while the outer cylinder is adiabatic and, the viscous and Joule dissipations are taken into consideration. The governing momentum and energy equations are solved numerically using the finite difference approximations. The velocity, the temperature, the volumetric flow rate and the average Nusselt number are computed for various values of the physical parameters.

6

Badania analityczne rozkładu ciśnienia w przepływie polimeru przy użyciu modelu płynu Binghama w kanałach stożkowych

Michalski D., Walicki E., Walicka A., Jurczak P.

Inżynieria i Aparatura Chemiczna

|

2006

|

Nr 6s

152-154

EN

Flow of molten polymer in conical channels is considered in the paper. To describe the problem a model of viscoplastic fluid is used but the final results are illustrated by Bingham fluid flow. The dimensionless formulae for pressure distributions in conical annular channels with inertia effects are presented.

7

The study of pressure drops in the flow of a polymer modeled as a bingham fluid in conical channels

Michalski D., Walicki E., Walicka A.

International Journal of Applied Mechanics and Engineering

|

2006

|

Vol. 11, no 2

359-369

EN

Technologies applied in polymers processing are permanently improved due to updating the knowledge on material proprieties, processes and phenomena during the processing. To determine the pressure distribution, one should define the geometrical shape of a channel, in the flow will be held the flow. The aim of calculations carried out is to determine the possibility of mathematical modelling of polymer flows between conical parallel surfaces. In this work, the flow of a polymer in conical channels was considered. To describe a melted polymer the model of a viscoplastic fluid was used but final results were illustrated by a flow of the Bingham fluid. The Bingham fluid chosen to modelling the flow of a polymer may by considered as legitimate, because its use will allow us to illustrate analytical methods of calculations. For the flow configuration and model under consideration the geometrical sizes of the channel and material coefficients of the fluid will be chosen on the basis of experimental data contained in literature. In the article, the on defining dimensionless pressure distribution for the flow in a conical channel as well as in a conical annular channel with the influence of inertia were presented. The results of calculations were introduced in tabular forms as well as in graphic forms.

8

The simulation of the annular flow of ERF with the inhomogeneity of electrical field strength

Bilyk V. A., Makhaniok A. A.

International Journal of Applied Mechanics and Engineering

|

2003

|

Vol. 8, no spec.

195-200

EN

The simulation of the annular flow of electrorheological fluid (ERF) is the actual task because this type of flow is applied to industrial devices (damper, shock absorber and etc). Rheological ERFs depend on electrical field strength. The purpose of this work is simulation of Bingham ERF flow in annular gap taking into account the inhomogeneity of electrical field strength. The results of flow curve analysis in some Bingham ERFs and own models which describe dependence between yield stress, plastic viscosity and electrical field strength have been presented. These models have been used at analytical solving of hydrodynamic problem. The obtained analytical solution allows to perform the hydrodynamic calculation of Bingham fluid flow in annular gap when yield stress and plastic viscosity depend on the inhomogeneity of electrical field strength.

9

Variational Analysis of a Frictional Contact Problem for the Bingham Fluid

Awbi B., Selmani L., Sofonea M.

International Journal of Applied Mathematics and Computer Science

|

1999

|

Vol. 9, no 2

371-385

EN

We consider a mathematical model which describes the flow of a Bingham fluid with friction. We assume a stationary flow and we model the contact with damped response and a local version of Coulomb's law of friction.The problem leads to a quasi-variational inequality for the velocity field. We establish the existence of a weak solution and, under additional assumptions, its uniqueness. The proofs are based on a new result obtained in (Motreanu and Sofonea, 1999). We also establish the continuous dependence of the solution with respect to the contact conditions.