Internship | Multiphase simulations acoustic-flow interaction at cavities

About this position

Internally corrugated hoses can generate high amplitude tonal sound (called singing or whistling) due to a coupling between the shear layers formed at each cavity and the acoustic field. Small fractions of liquid will limit the amplitude or even eliminate the singing. Liquid injection can even be used for mitigation purposes. Although the main mechanisms of the mitigation of singing are understood, qualitative predictions are difficult.

Therefore in this study, it is attempted whether CFD can be used to determine the required liquid fractions for the suppression of singing. In this internship the aim is two-fold:

Extend the work to field conditions (larger diameter, higher Reynolds, lower liquid fraction)
Evaluate if the influence on the acoustic performance can be determined by combining the two phase simulations with acoustics source modeling

Evaluate field case results. A number of field trials were done. By doing CFD on the actual conditions, the field experience is to be linked to CFD results.

The final goal is to come to a simulation procedure in which the effect of liquid on singing can be calculated.

This works can be done as a work placement internship of 3 months in which the focus will be on field cases or as graduation project in which the focus is on the methodology development.

• Review literature on CFD modelling of thin films at large scale and high Reynolds.
• Extend existing research to field conditions (larger diameter, higher Reynolds, lower liquid fraction).
• Calculate acoustic performance of cavity with and without liquid and calculate a field case.

• MSc student in Mechanical Engineering, Aerospace Engineering or a related discipline.
• Strong interest in fluid mechanics and numerical modelling.
• Experience with CFD software (e.g., ANSYS Fluent, Openfoam or equivalent) is required.
• You can work independently on different aspects of scientific research, including literature review and academic writing.
• You are collaborative and proactive.
• You are available to work on location in Rijswijk.

Internship at TNO means working in an environment where substance and impact are central. You will become part of a knowledge organisation where research and practice come together, and where experts collaborate on solutions to current societal and technological challenges. Your internship is a period in which you can discover what suits you, where your strengths lie and what you would like to learn next.

You are part of a professional working environment, gain insight into how things work in practice, and have the opportunity to build experience that goes beyond this internship alone. For many students, an internship is therefore also a first step in discovering whether TNO could be a potential next step after graduation.

• A professional and innovative internship environment in which you actively contribute to societal and technological challenges, working alongside leading experts in your field.
• Personal and dedicated supervision, with focus on your learning objectives, development and study assignment.
• Room to develop: you gain relevant work experience, develop both your subject‑specific and professional skills, and build a valuable network.
• Use of a laptop and the facilities you need to perform your work effectively.
• A monthly internship allowance of € 615 for a full‑time internship, for MSc, BSc and vocational education (MBO) students.
• Up to eight hours of leave per internship month for a full‑time internship, allowing you to balance your internship with your studies and personal life.
• A contribution towards travel expenses if you are not entitled to a student travel card.
• A free membership to Jong TNO: the network for young colleagues, where you can meet other TNO colleagues and participate in sports activities, professional and personal development activities, and social events such as the annual ski trip.

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