Description of the thesis topic

At the CNRS on the Futuroscope site, the PPrime Institute is recruiting a PhD student to study the experimental and numerical aspects of the research project funded by the ANR / ASTRID-MOCODYN.

Work Context

The proposed doctoral contract involves setting up, executing, and evaluating a new high-frequency pulsed actuator technology with high authority potential (supersonic ejection speed with high enthalpy). This actuator is based on technology initially proposed by Johns Hopkins University. The device uses two or three electrodes positioned within a small-volume cavity. An electric discharge is generated in this volume to sharply increase pressure and temperature, expelling air at high speed. After the ejection, fresh air mixes with the hot air for the next pulse, producing zero mass flux jets. These actuators offer precise control of high-speed airflows, up to 400 m/s, thanks to their fast electrical operation, surpassing traditional systems, especially in terms of usable frequency range. The concept being studied is a plasma synthetic jet actuator with temporal modulation, driven by ionization of the inter-electrode space. In this research program, the system, called the Sonic Throat Plasma Jet (JPS), uses an external pressure supply to create a sonic jet, with the electric discharge providing precise control of the output flow modulation.

The work to be done is both numerical and experimental. The first step will involve optimizing the shape of the cavity and the minimum energy required to modulate the ejection speed of the control system. This initial stage, performed ahead of the experimental tests, will be carried out through numerical modeling of the problem. Simultaneously, preliminary experimental tests will be conducted to establish a database essential for validating the numerical approach. In the second phase, the actuator prototype will be developed based on the numerical results and its electro-thermo-mechanical characterization will be carried out. Finally, the control system will be replicated, integrated onto a nozzle model, and tested under supersonic flow conditions.

The PhD student will be based at the Pprime Institute at ENSMA.
The work will be carried out in collaboration between the EFD and 2AT research teams.

The candidate must hold a Master's degree with solid experience in fluid mechanics, thermodynamics, heat transfer, and electrical engineering.

Particular attention will be focused on the following points:
-an affinity for experimental work,
- an attention to detail,
- an analytical skills, and critical thinking abilities.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

Short-term trips, both within France and abroad, are to be expected.

Additional Information

- Start of the thesis on 1 November 2024.
- Registration at the University of Poitiers: MIMME doctoral school.