Polymer Drag Reduction in Single Phase Turbulent Fluid Flows
Lead Research Organisation:
University of Leeds
Department Name: Chemical and Process Engineering
Abstract
Context:
Process efficiency is at the forefront of scientific challenges due to the demand for lower global energy consumption. To achieve efficiency gains in "big-energy" processes, modifications of the chemical and physical properties are required. Chemical additives such as drag reducing agents, which are used to modify pipeline pressure drops, have undoubtedly led to reductions in overall pumping power requirements. However, the mechanism for drag reduction is not adequately understood due to a lack of attention given to the chemical-fluid interactions in the fluid and at the solid-liquid interface. The complexity of fluid turbulence and polymer dynamics has resulted in no obvious pathway for drag reduction optimization by chemical additives. Predicting the magnitude of drag reduction from polymer properties is not yet achievable.
Aims and Objectives:
The overall research aim is to better understand the mechanism(s) by which polymers promote drag reduction. Research objectives include: i) study the influence of polymer structure on the magnitude of drag reduction and the robustness of polymer to degradation; ii) consider the effects of polymer adsorption on solid surfaces, and its contribution to the overall drag reduction performance; iii) investigate the behaviour of polymers in the fluid boundary layer using a home-built Couette cell with particle imaging velocimetry; iv) complement experimental findings to those predicted via simulation.
Potential Applications and Benefits:
By developing a fundamental understanding of polymer drag reduction it will be possible to design smarter chemicals that deliver optimum drag reduction performance properties (high drag reduction, chemically robust in challenging environments, low additive concentrations). Reducing drag in fluids has broad application from large transport pipelines (crude oil) to small flow channels (micro-fluidics, cooling circuits etc.). Achieving optimum drag reduction will enable technology to advance where friction, pressure drop, currently impede performance and function.
Process efficiency is at the forefront of scientific challenges due to the demand for lower global energy consumption. To achieve efficiency gains in "big-energy" processes, modifications of the chemical and physical properties are required. Chemical additives such as drag reducing agents, which are used to modify pipeline pressure drops, have undoubtedly led to reductions in overall pumping power requirements. However, the mechanism for drag reduction is not adequately understood due to a lack of attention given to the chemical-fluid interactions in the fluid and at the solid-liquid interface. The complexity of fluid turbulence and polymer dynamics has resulted in no obvious pathway for drag reduction optimization by chemical additives. Predicting the magnitude of drag reduction from polymer properties is not yet achievable.
Aims and Objectives:
The overall research aim is to better understand the mechanism(s) by which polymers promote drag reduction. Research objectives include: i) study the influence of polymer structure on the magnitude of drag reduction and the robustness of polymer to degradation; ii) consider the effects of polymer adsorption on solid surfaces, and its contribution to the overall drag reduction performance; iii) investigate the behaviour of polymers in the fluid boundary layer using a home-built Couette cell with particle imaging velocimetry; iv) complement experimental findings to those predicted via simulation.
Potential Applications and Benefits:
By developing a fundamental understanding of polymer drag reduction it will be possible to design smarter chemicals that deliver optimum drag reduction performance properties (high drag reduction, chemically robust in challenging environments, low additive concentrations). Reducing drag in fluids has broad application from large transport pipelines (crude oil) to small flow channels (micro-fluidics, cooling circuits etc.). Achieving optimum drag reduction will enable technology to advance where friction, pressure drop, currently impede performance and function.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509681/1 | 01/10/2016 | 30/09/2021 | |||
| 2042717 | Studentship | EP/N509681/1 | 01/10/2017 | 30/09/2021 | Stefanos Michaelides |
| Description | We studied the influence of charged polymer conformation on the fluid properties finding out that the overall drag reduction is becoming more stable at constant shears when the charges of the polymer are at least partially shielded, making the process of drag reduction more efficient over time. |
| Exploitation Route | There is a need to develop models that are able to predict the loss of DR that is a function of the polymer properties (mechanical properties, aggregation state, conformational state, relaxation time). Our experiments provide some useful empirical data that will help towards the ultimate goal which is prediction of the "degradation". |
| Sectors | Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Energy,Environment,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Transport,Other |
| Description | CRODA collaboration |
| Organisation | Croda Europe Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We formed this collaboration on the basis of gaining industrial insight into the practical applications of the project. We also collaborated in the synthesis of some high molecular weight polymer that have been tested as part of the PhD. |
| Collaborator Contribution | Provision of chemicals for polymer synthesis and very useful expertise and knowledge about acrylic polymer synthesis. |
| Impact | The project is multidisciplinary in nature (fluid mechanics, rheology, colloids, polymer engineering). Knowledge of polymer engineering gained from sponsor, Knowledge of polymer drag reduction gained by sponsor. |
| Start Year | 2017 |