Missions

Within the current environmental context, the energy efficiency of buildings is a major challenge. Building envelopes, designed to protect occupants from external climatic variations, play a key role. Over the past 50 years, numerous models have been developed to represent the physical phenomena within these envelopes. A bibliographic review is provided in [woloszyn 2008] with a recent update in [Mendes 2019].

Despite the existence of numerous simulations tools, the building envelopes are still designed according to two principles: (i) First, the enclosures are considered as planar barriers against external climatic variations. The incident radiation and convective heat flux are assumed to be uniform [Berger 2021]. (ii) Second, the envelopes are composed by association of multiple plane layers of different materials.

Considering these observations, the following scientific question emerges: can the energy efficiency be increased by carrying topology and shape optimization of the building envelopes? Several preliminary studies have partially addressed this question using a numerical approach: [Karashabyeva 2025] proposes a topological optimization for a steady-state heat transfer case, while [Alpar 2024, Alpar 2025] addresses shape optimization in both steady-state and transient regimes.
The objective of this post-doctoral project is to develop an experimental prototype of a wall resulting from topological and/or shape optimization to minimize thermal losses.

Activités

To achieve this, the following steps will be implemented.
- First, scaling laws (or similarity laws) for the prototype will be established.
- Then, a reduced-scale wall model will be developed, either through molding techniques or 3D printing.
- The prototype will then be placed in a bi-climate chamber to control temperature conditions. An experimental setup will be designed to reproduce the incident radiative fluxes of the real wall model.
- Finally, the last step will involve generating experimental data on the temperature fields within the wall. These data will serve as a benchmark to validate the numerical predictions of the models.

Compétences

The profile sought is that of a researcher, specializing in experimental design for the investigation of heat transfer phenomena. A rigorous methodology for monitoring is required. Skills in the use of similarity laws would be beneficial.

Résultats attendus et contrôles

- experimental data of temperature in a wall submitted to a transient and bi-dimensional excitation
- experimental benchmark with numerical predictions
- publications in peer-reviewed journals

Contexte de travail

Placement: La Rochelle Université, laboratory LaSIE, UMR 7356 CNRS
Recruitment: fixed-term contract 12 months
Working hours: full time
Contract starting: Spring 2026
Salary: According to level of experience and degree of expertise, with reference to the A category salary scale, equivalent to a research engineer.

The work will be supervised by Julien Berger (CNRS) and carried out at LaSIE in La Rochelle. Meetings and scientific collaborations will be planed in France and abroad.

The LaSIE is a joint research unit (UMR 7356) between CNRS and La Rochelle University, dedicated to the investigation of heat transfer for engineering applications. The LaSIE brings together some 160 researchers, engineers and administrative staff, including 60 permanent employees and several dozen graduate students. The LaSIE joint research activities in several engineering domain such as civil engineering, energy and environment, transfer in material and fluid mechanics. The student will take part in team meetings and attend the many seminars offered at LaSIE.