On the Development of a Novel Approach in Modelling of Turbulent Pulsating Flows

Lead Research Organisation: Liverpool John Moores University
Department Name: School of Engineering

Abstract

Unsteady flows in which the bulk or free-stream velocity varies with time arise in many engineering systems / natural environment. Examples of applications and the challenges that they pose are highlighted in numerous recent publications include: i) The pulsatile blood flows in carotid and coronary arteries, for example, where a majority of atherosclerosis is observed; ii) The transient events at a nuclear power plant during various hypothetical fault conditions are the most vulnerable conditions which impose severe constraints on plant operations.

The project will establish a new approach in study pulsating flow which will fundamentally change how unsteady turbulent flow is perceived leading to fundamental improvements in: a) understanding of pulsating flows; b) simulations of unsteady flows using turbulence modelling, b) turbulent flow control and the way that the unsteady friction models are formulated. This will result in improved: predictive capability of a blood periodic transient flow; drag reduction that utilises pulsating flows, safety and economy of nuclear reactors; efficiency of turbomachinery and wind turbines, water resources efficiency and protection of coasts. Moreover, the projects will result a high-fidelity, high-scalability in-house CFD (Computational Fluid Dynamics) package which will support future collaborations.

A comprehensive programme of numerical simulations will be conducted to study the flow at wide range of pulsating parameters and Reynolds numbers. An in-house DNS (direct numerical simulations) / LES (large eddy simulations) package will be used to investigate detailed flow structure and turbulence statistics for the flow. Results of the cases associated with pulsatile blood flows in arteries, will be analysed against experimental data provided by the Translational Biomedical Research Centre, University of Bristol, who will act as the project partner to the research.

Planned Impact

This research project will have the following impacts in the UK and beyond:
Long-term impact: Unsteady flows are commonplace in engineering applications (especially the energy, water and transport sectors), nature and the human body. The success of the proposed research will enable a step change in the understanding and predictive capabilities of unsteady flows, which will lead to long-term impact, including for example: improving predictive capability of blood periodic transient flow in pulsating blood flows, improving drag reduction using pulsating flows, improving the safety and economy of new nuclear reactor designs, improving the efficiency of turbomachinery and wind turbines, more efficient use of water resources and better protection of coastal lines. The project will also help to maintain the UK's strength in transition research. More specifically, the proposed research will establish a new approach in study pulsating flow, which will fundamentally change how unsteady turbulent flows is perceived: the complex unsteady turbulent flow will be pertinently interpreted as a laminar boundary layer followed by turbulent-transition. This will lead to fundamental improvement on the methodologies for simulations of unsteady flows using turbulence modelling, the approaches towards flow control and the way that the unsteady friction models are formulated. Moreover, the high-fidelity, high-scalability in-house CFD package will be available to the community hence will provide further potentials for future collaborations.

Environmental Impact: The drag reduction performance improvements targeted for pulsating flows will have a beneficial environmental impact. The project contributes to the national priorities of improving energy efficiency and sustainability, an issue that is currently high on government agendas around the world and the subject of UK Government policy consultations relating to methods leading to UK to become a "world leader in low emission transport". A 10% friction reduction could save £4 bn/yr in shipping alone.

Health care: The project targets at providing some scaling parameters for pulsating blood flows over a wide range of flow conditions, hence will advance our understanding toward a predictive, rather explanatory, approach. Therefore, it will shed some light into modelling the dynamic mechanism of blood flow, which would help to prevent some deadly disease associated with such flow. In the UK, almost 180,000 deaths were attributed to Cardiovascular disease (CVD) in 2011, where the total economic cost (including healthcare and informal care costs and loss of productivity) of the disease was £18.9 billion.

Publications

10 25 50
 
Description Despite a delay in start and lost momentum at early stages of the project (mainly due to impact of the COVID-19), we believe a good progress has been made on the project. The key achievements are as below:
- As per the project's plan, the early few months of the project, the major focus has been made on modification of the group's in-house Computational Fluid Dynamics (CFD) code and validation of the code for simulation of unsteady turbulent flows.
- Simulations on the projects have been performed on UK National Supercomputing Service, ARCHER/ARCHER2. There are however some outstanding simulations for cases with high Reynolds number and pulsating amplitudes, that will be completed by the end of the project.
- The project has proposed a novel theory for analysis of the pulsating flows.
Exploitation Route - A new collaboration has been established with University of Tehran. We hosted a visiting Professor from University of Tehran working on joint publications and future grant proposals. A joint journal paper on the experimental results has been published in September 2020.
- A GitHub repository and corresponding website are being developed in order to include the in-house code which is being adopted for simulation of unsteady flows and also the database to be obtained at later stage of the project.
- Discussions with few industrial and academic partners are in progress.
- A successful application has been made to LJMU for a fully-funded PhD student who will undertake complementary roles to the project. The studentship has been successful and PhD student is currently working on the project.
- A new collaboration has been established with Sandon Global Engraving Technology Ltd (Sandon), as a world leading company in manufacturing Anilox rollers which sit at the heart of printing presses. The project contributes to improve development of accuracy of modelling prediction of ink flow behaviour over new generation Anilox rolls generation Anilox roll.
- A new collaboration is being established between the project team, NHS, and School of Sport and Exercise Sciences. The project aims at studying behaviour of blood flows in arteries with stenosis diseases.
Sectors Aerospace

Defence and Marine

Energy

Healthcare

Manufacturing

including Industrial Biotechology

Transport

 
Description Despite a delay in start and lost momentum at early stages of the project, the results obtained from the research are being used to improve development of accuracy of modelling prediction of ink flow behaviour over new generation of Anilox rolls which are under development by a world-leading company, Sandon Global Engraving Technology Ltd (Sandon). From fundamental fluid dynamics research point of view, the project has proposed a novel theory for analysis of the pulsating flows. Two journal articles have been submitted to the leading international journal in the subject and are currently under review. We would however expect major non-academic impact of the project to be seen at later stages once the journal articles have been published and also a recent collaboration on a project in the subject of behaviour of blood flow in the stenosis arteries has been progressed further. Finally, the project simulation results have been produced, analysed, disseminated and used by the academic/non-academic project partners and related industries in particular those who are outlined in the pathway to impact. Part of the results have been disseminated through a journal paper published in the Journal of Fluid Mechanics in March 2024.
First Year Of Impact 2021
Sector Energy,Healthcare,Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description Development of Very Low Head Tidal Turbine
Amount £1,379,278 (GBP)
Funding ID 10072702 
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 11/2023 
End 01/2026
 
Description Development of next generation of Anilox Rolls and Sleeves
Amount £396,431 (GBP)
Organisation Liverpool John Moores University 
Sector Academic/University
Country United Kingdom
Start 01/2020 
End 06/2021
 
Title DNS database for pulsating flows 
Description Database has been prodcued for the pulsating simulations results which have been generated from the project. The data are currently saved on a ARCHER and a University storage but will be uploaded and made available to a wider research community at the later stage of the project. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? No  
Impact The dataset can be used for various puposes, including i) to be used by the researchers to further analysis and progress our understanding about of the important types of flow, ii) to be used by turbulence model developer to improve accuracy of such models to predict flow behaviour. 
 
Title In-house CFD code 
Description The group's in-house direct numerical simualtion (DNS) and large eddy simulation (LES) code is being developed further and made available to the community via GitHub. 
Type Of Material Computer model/algorithm 
Year Produced 2020 
Provided To Others? No  
Impact Preparation of database and a website for the project are in progress and will be made available to publib at later stage of the project. 
 
Description Collaboration with School of Sport and Exercise Sciences 
Organisation Liverpool John Moores University
Department Centre for Sport and Exercise Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Part of the results of the simulations related to blood flow in large arteries have been discussed with Prof. Dick Thijssen as a leading expert in the area of influence of exercise in the performance of Cardiovascular systems.
Collaborator Contribution Prof. Thijssen has provided some very constructive comments and insight about the results.
Impact multi-disciplinary
Start Year 2023
 
Description Collaboration with University of Isfahan 
Organisation University of Isfahan
Country Iran, Islamic Republic of 
Sector Academic/University 
PI Contribution A collaboration has been established between Transient flow Lab (Liverpool John Moores University) and ThermoFluids group (University of Isafahn). The unsteady DNS data prodcued on our EPSRC project used to validate and further development of RANS simulations have been carried out at University of Isafahn. The results are currently being prepared for a joint publication.
Collaborator Contribution The partner used our DNS data to validate and further development of their RANS models. They are also drafting a joint journal article using the results.
Impact A journal article is in preperation
Start Year 2021
 
Description Collaboration with University of Tehran 
Organisation University of Tehran
Country Iran, Islamic Republic of 
Sector Academic/University 
PI Contribution A collaboration has been established between Transient flow Lab (Liverpool John Moores University) and Aerodynamics lab (University of Tehran). The unsteady experimental data obtained from physical wind tunnel experiment at University of Tehran have been analysed and joint publication produced accordingly. Ongoing collaboration between the two groups is in progress towards join grant proposal.
Collaborator Contribution A collaboration has been established between Transient flow Lab (Liverpool John Moores University) and Aerodynamics lab (University of Tehran). The unsteady experimental data obtained from physical wind tunnel experiment at University of Tehran have been analysed and joint publication produced accordingly. Ongoing collaboration between the two groups is in progress towards join grant proposal.
Impact Tabrizian A, Tatar M, Masdari M, Eivazi H, Seddighi M. 2020. An experimental study on boundary layer transition detection over a pitching supercritical airfoil using hot-film sensors International Journal of Heat and Fluid Flow, 86.
Start Year 2020
 
Title CHAPSim 
Description CHAPSim is an in-house direct numerical simulation (DNS) and large eddy simulation (LES) code which is initially developed by the PI and expanded over the past 15 years for simulation of channel and pipe flows. The code is being adopted on this project, for simulation of periodic and non-periodic flows. Update (March 2022): The code has been successfully adopted for use in the EPSRC project to simulate and post-process both steady and unsteady flows. 
Type Of Technology Software 
Year Produced 2021 
Open Source License? Yes  
Impact The code is selected by CCP for nuclear thermal hydraulics to be further developed for thermal flows and be used as a community code for study thermal hydraulics and also unsteady flows. A GitHub repository and website are being created for the code to make the software available to public and enhance further its impact. 
 
Description Attendance at UK Turbulence Consortium annual meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact The outcomes of the funded EPSRC project were presented in the meeting and discussed with other colleagues. A collaboration is being undertaken for a follow-up project.
Year(s) Of Engagement Activity 2023
 
Description CCP for nuclear thermal hydraulics and Turbulence 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Meetings have been held with CCP nuclear thermal hydraulics and Turbulence key researchers. This meeting discussed potential collaborations. Information on the key features of codes developed by each CCP is exchanged.
Year(s) Of Engagement Activity 2020,2021