Model of layered flow of viscous-plastic Bingham fluid in the extruder channel
https://doi.org/10.20914/2310-1202-2018-2-58-63
Abstract
The analysis is carried out and the presence of a zone of a piston flow, which has a significant influence both on the process of extrusion, and on the determination of the discharge-pressure characteristics of the screw, is established. It is noted that the effective viscosity has a physical meaning if the shear rate to which it corresponds is indicated. The effective viscosity is considered to consist of two components: the plastic viscosity corresponding to the viscosity of the Newtonian fluid and the structural viscosity that characterizes the shear resistance caused by the tendency of the solid particles contained in the Bingham liquid to form a structure. The effective viscosity is introduced into many hydrodynamic equations if the shear rate to which it corresponds is known. In the auger channel there are zones of forced flow created by the dynamic shear stress and the reverse flow of the head resistance created by the overpressure. The shear rate in the auger channel is marked by considerable heterogeneity and determines the complex nature of the shear deformation of the material during extrusion. Regardless of the pressure amplitude, the rigid core can not completely disappear, because for very small dimensions of the nucleus the pressure value must be very large, and with the disappearance of the plastic flow it must become infinite. Thus, the dependence of the shear stress on the shear rate for the flow of a Bingham viscoplastic fluid is always nonlinear for any values of the shear rate. An important element in the calculation of the discharge-pressure characteristics of the extrusion process is the localization of the plastic flow in the screw channel. As a result of the analysis of the model of the layered flow of viscoplastic Bingham liquid in the extruder channel, it is established that there is a zone of piston flow that exerts a significant influence both on the process of extrusion and on the determination of the discharge and pressure characteristics of the screw.
About the Author
A. V. Gukasyan
Kuban state technological university
Russian Federation
Cand. Sci. (Engin.), associate professor, Technological Equipment and Life Support Systems Department, Krasnodar, Moskovskaya 2, 350072, Russia
Russian Federation
Cand. Sci. (Engin.), associate professor, Technological Equipment and Life Support Systems Department, Krasnodar, Moskovskaya 2, 350072, Russia
References
1. Zaslavets A.A., Shalyakhov A.A., Koshevoi E.P., Kosachev V.S. Hydraulic of the reverse flow inside the contactor membrane. Novye tekhnologii [New technologies] 2013.no. 2. pp. 91-94. (in Russian)
2. Kosachev V.S. Povyshenie effektivnosti rafinatsii masel v my’no-shchelochnoi srede [Improving the efficiency of oil refining in the soap-alkaline environment on the basis of studying the physico-chemical features of the process] Krasnodar, Krasnodar Order of the Red Banner of Labor, Polytechnic Institute, 1985. 28 pp. (in Russian)
3. Kosachev V.S. Teoreticheskie I prakticheskie osnovy oslozhnennoi PAV massoperedachi [Theoretical and practical foundations of mass transfer complicated by surface-active substances in the process of oil refining] Krasnodar, Kuban State Technological University, 1998. 48 p. (in Russian)
4. 4 Meretukov Z.A., Zaslavets A.A., Koshevoi E.P., Kosachev V.S. Methods for solving differential equations of hydrodynamics. Novye tekhnologii [New technologies]. 2012. no 1. pp. 36-41. (in Russian)
5. Meretukov Z.A., Kosachev V.S., Koshevoi E.P. Solution of the problem of non-linear porosity during spinning. Izvestiya Vysshikh Uchebnykh Zavedenii. [News of universities. Food technology] 2011. no. 5-6 (323-324). pp. 62-64. (in Russian)
6. Podgorny S.A., Kosachev V.S., Koshevoi E.P., Shalyakhov A.A. Moisture-temperature kinetic dependencies during drying. Novye tekhnologii [New technologies]. 2014. no. 1. pp. 43-47. (in Russian)
7. Bingham Medalists. The Society of Rheology. Available at: http://www.rheology.org.
8. Podgorny S.A., Koshevoi E.P., Kosachev V.S., Zverev S.V. Statistical estimation of the cluster model of grain hygroscopicity. Khranenie I pererabotka sel’khozsyr’ya [Storage and processing of agricultural raw materials] 2011.no. 6. pp. 11-14. (in Russian)
9. Podgorny S.A., Koshevoi E.P., Kosachev V.S., Shalyakhov A.A, Statement of the task of describing heat transfer, mass and pressure during drying Novye tekhnologii [New technologies] 2014.no. 3. pp. 20-27. (in Russian)
10. Podgorny S.A., Meretukov Z.A., Koshevoi E.P., Kosachev V.S. Finite element method in solving heat conduction problems. Vestnik VGUIT [Proceedings of Voronezh State University of Engineering Technologies] 2013. no. 2 (56). pp. 10-15. (in Russian)
11. Shalyakhov A.A., Vereshchagin A.G., Kosachev V.S., Koshevoi E.P. Development of a condensation model for vapor-gas mixtures with polymeric hollow fiber membranes. Novye tekhnologii [New technologies]. 2009. no. 1. pp. 39-43. (in Russian)
12. Gukasyan A.V. Identification of rheological dependencies of oil material processed in a screw press. International Journal of Mechanical Engineering and Technology. 2017. vol. 8. no. 10. pp. 708–718.
13. Gukasyan A.V. Analysis of factors of the process of pressing vegetable oil in a screw press. Izvestiya Vysshikh Uchebnykh Zavedenii. [News of universities. Food technology] 2017. no. 4 (358). pp. 64-68. (in Russian)
14. Karmanova O.V., Muromtsev D.N., Pichkhidze S.I. Influence of mixing parameters on the rheological and surface appearance characteristics of rubber compounds unshaped profiles. Vestnik VGUIT [Proceedings of the Voronezh State University of Engineering Technologies]. 2014. no. 3. pp. 118-121. (in Russian)
Review
For citations:
Gukasyan A.V. Model of layered flow of viscous-plastic Bingham fluid in the extruder channel. Proceedings of the Voronezh State University of Engineering Technologies. 2018;80(2):58-63. (In Russ.) https://doi.org/10.20914/2310-1202-2018-2-58-63
Views:
727
Email this article 
Post a Comment 
