High-Pressure Diesel Spray

Numerical and Experimental Investigation on High-Pressure Diesel Spray

Degree type


Closing date

27 March 2023



Citizenship requirement


About the research project

Global concerns to reduce emissions are continuously forcing manufacturers to improve the efficiency of engines by optimising fuel injection systems and combustion process. Despite the wide use of injectors, the key physics of the fuel injection processes are not yet fully understood imposing a significant challenge for the development of more efficient injection system and combustion processes. The primary atomisation of the liquid fuel jet occurs in the region close to the nozzle exit, influences secondary atomisation, spray dynamics, air-fuel mixture quality, and ultimately the entire combustion process. Complex and concurrent physics associated with primary and secondary atomisation of liquid fuel induce more constraints for researchers to experimentally characterise the effect of phenomena such as swirl flow, flow separation, cavitation, and turbulence on spray dynamics.

These limitations can be tackled by the means of numerical modellings which provide a clearer understanding of spray dynamics involving transition from liquid jets to fine droplets. Numerical models which are used in the design of fuel injectors are subjected to further developments through the inclusion of recent research findings. Experimental tests conducted within the AMC's constant volume high-pressure spray chamber provide a qualitative and quantitative database to evaluate and validate numerical modelling results. The present work focuses on processes in the nozzle and the first several nozzle diameters after the nozzle exit of a single-hole solid cone injector.

High fidelity numerical models can be utilised to characterise detailed evolution of fuel spray from liquid jets to dispersed small scale droplets. The use of high-resolution numerical schemes and flux reconstruction algorithms can deal with highly turbulent flow phenomenon that occur with great variation in spatial and time scales. Highly accurate results predicted by the developed high-resolution numerical methods can act as an indispensable supplement to existing experimental observations and measurements which contribute to the optimisation/development of next generation low emission and high thermal efficiency combustion engines.

Primary Supervisor

Meet Dr. Javad Mehr


Applicants will be considered for a Research Training Program (RTP) scholarship or Tasmania Graduate Research Scholarship (TGRS) which, if successful, provides:

  • a living allowance stipend of $31,500 per annum (2023 rate, indexed annually) for 3.5 years
  • a relocation allowance of up to $2,000
  • a tuition fees offset covering the cost of tuition fees for up to four years (domestic applicants only)

If successful, international applicants will receive a University of Tasmania Fees Offset for up to four years.

As part of the application process you may indicate if you do not wish to be considered for scholarship funding.


Applicants should review the Higher Degree by Research minimum entry requirements.

Selection Criteria

The project is competitively assessed and awarded.  Selection is based on academic merit and suitability to the project as determined by the College.

Essential criteria :

  • Good understanding of fluid mechanics specifically in the framework of high-pressure and compressible flows.
  • Good understanding of CFD theories including pressure-velocity coupling, heat and mass transfer, multiscale modelling in the framework of compressible flow.
  • Experience in OpenFOAM (experience in structured mesh generation and high order numerical scheme are preferred).
  • Awarded a First Class Honours degree or hold equivalent qualifications or relevant and substantial research experience in an appropriate sector.
  • Ability to demonstrate strong research and analytical skills.
  • First author of at least two published (or accepted) high-ranked journal papers.

Desirable criteria:

  • Experience in high pressure fuel injection system.
  • Experience in developing explicit/implicit method for all Mach number flows.
  • Experience in data processing using Python.
  • Experience in C++.
  • Ability to conduct spray chamber testing and work to assemble, disassemble and commission new injection systems.

Application process

There is a three-step application process:

  1. Select your project, and check you meet the eligibility and selection criteria;
  2. Contact the Primary Supervisor, Dr. Javad Mehr to discuss your suitability and the project's requirements; and
  3. Submit an application by the closing date listed above.
    • Copy and paste the title of the project from this advertisement into your application. If you don’t correctly do this your application may be rejected.
    • As part of your application, you will be required to submit a covering letter, a CV including 2 x referees and your project research proposal.

Following the application closing date applications will be assessed within the College. Applicants should expect to receive notification of the outcome by email by the advertised outcome date.

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