Thesis worker

Master Thesis – Development and Experimental Validation of a Predictive Common-Rail Pressure Wave Model

Background

In modern diesel engines, precise fuel injection control is essential for achieving optimal engine performance, fuel efficiency and emission characteristics.

During and after fuel injection events, pressure waves and oscillations occur within the common-rail fuel injection system. These pressure fluctuations can influence subsequent injection events, particularly in multiple-injection strategies, affecting fuel delivery accuracy and injection consistency.

Understanding and predicting these pressure oscillations is therefore important for improving fuel injection system performance.

Objective

The objective of this Master's thesis is to develop and experimentally validate a predictive mathematical model capable of estimating pressure wave behaviour in the common-rail system following fuel injection events.

The work will investigate physics-based modelling approaches, including second-order or higher-order dynamic system representations, considering the influence of fuel properties and injection operating conditions.

Thesis Responsibilities

The student will:

• Conduct a literature review on hydraulic pressure wave propagation and oscillations in common-rail injection systems.
• Investigate suitable mathematical modelling approaches, including mass–spring–damper analogies or other physics-based methods.
• Plan and perform experiments using a fuel injection test rig to characterize pressure oscillations under different operating conditions.
• Analyze experimental pressure signals to identify key characteristics such as oscillation frequency, amplitude and damping behaviour.
• Develop a predictive model using MATLAB/Simulink or equivalent simulation tools.
• Investigate the influence of rail pressure, injected fuel quantity and injection timing on pressure wave behaviour.
• Validate and refine the developed model using experimental measurements.
• Evaluate the model's predictive accuracy and identify opportunities for future applications, such as virtual pressure sensing.
• Document and present the methodology, experimental results and conclusions.

Desired Qualifications and Skills

We are looking for a motivated Master's student specializing in Mechanical Engineering, Automotive Engineering, Mechatronics, Applied Physics or a related field.

Required or relevant skills:

• Good understanding of fluid mechanics, hydraulics and dynamic systems.
• Knowledge of mathematical modelling, differential equations and system dynamics.
• Experience with MATLAB/Simulink or similar simulation environments.
• Basic understanding of signal processing and experimental data analysis.
• Interest in fuel injection systems and automotive engineering.
• Strong analytical, problem-solving and communication skills.

Desirable:

• Experience in simulation using GT Suite/Python.
• Experience in AI/Language Learning Models

Experience with experimental testing, system identification or fuel injection technology is considered an advantage.

Thesis Information

Thesis level: Master's thesis

Number of students: 1

Location: Södertälje, Sweden

Company: Scania

Start date: To be agreed upon