AP23486543 – Modeling of turbulent flow and heat transfer of a high-viscosity fluid with anti-turbulence additives

Objective of the project – Modeling and creation of a methodology for calculating turbulent flow and heat transfer of high-viscosity oil with anti-turbulence additives.

Relevance: The relevance of the project is determined by the widespread occurrence of turbulent fluid flows in pipes in industries such as oil production, energy, and chemical engineering. Reducing hydraulic resistance using polymer additives opens significant opportunities for improving the energy efficiency of oil transportation. The study of the Toms effect allows for a deeper understanding of the mechanisms of turbulence generation and control. This is important for the development of more efficient technologies for fluid flow management. Currently, non-isothermal turbulent flow of high-viscosity oil with polymer additives has not been sufficiently studied. Therefore, conducting such research is relevant for improving the efficiency and reliability of energy carrier transportation processes.

Scientific supervisor: Doctor of Technical Sciences, Professor, Uzak Zhapbasbayev

Expected and achieved results: During the project, a detailed analysis of modern turbulence models used to describe the flow of high-viscosity fluids with polymer additives was carried out. Key physical effects such as drag reduction and heat transfer reduction in turbulent flows were examined. RANS models (k–ε–v²–f, ARSM, RSM), as well as LES and DNS methods, were analyzed for more accurate flow description. It was established that RANS models are the most efficient for engineering calculations, while DNS provides high accuracy but requires significant computational resources. A mathematical model of non-isothermal turbulent flow and heat transfer of high-viscosity fluid with polymer additives was developed based on the FENE-P rheological model. Boundary conditions for the equations of motion and heat transfer in a pipe were determined. Numerical methods for solving the system of equations were developed using the SIMPLE algorithm and the finite volume method. Finite-difference analogues of the equations of motion, heat transfer, and turbulence were constructed using the QUICK scheme for approximating convective terms. The developed model was verified by comparison with DNS and RANS results for non-Newtonian power-law fluids. A satisfactory agreement between the calculated results and DNS/RANS data was established. Profiles of velocity distribution, turbulent kinetic energy, and Reynolds stresses were obtained, confirming the adequacy of the model. It was found that the turbulence level in non-Newtonian fluids is higher than in Newtonian fluids, and the structure of fluctuations differs by direction. It was determined that polymer additives reduce flow resistance by suppressing vortices and increasing the thickness of the buffer layer. Dependencies of viscosity on the flow behavior index were obtained, showing its increase toward the pipe axis. Comparison with experimental data for viscoelastic fluids (xanthan gum solution) confirmed the validity of the model and its applicability for engineering applications.

List of publications with links to them

1. Zhapbasbayev U., Bekibayev T., Pakhomov M., Ramazanova G.
   Heat Transfer of Crude Waxy Oil with Yield Stress in a Pipe // Energies. – 2024. – Vol. 17. – Article 4687. – DOI: https://doi.org/10.3390/en17184687
2. Pakhomov M. A., Zhapbasbayev U. K.
   RANS predictions of turbulent non-isothermal viscoplastic fluid in pipe with sudden expansion // Journal of Non-Newtonian Fluid Mechanics. – 2024. – Vol. 334. – Article 105329. – DOI: https://doi.org/10.1016/j.jnnfm.2024.105329
3. Zhapbasbayev U. K., Ramazanova G. I., Pakhomov M. A.
   Turbulent flow of viscoplastic fluid in a pipe with sudden expansion // Reports of the National Academy of Sciences of the Republic of Kazakhstan. – 2025. – Vol. 1. – No. 353. – P. 64–77