Liquid propelled rocket engines (LPRE) are highly non-linear systems that require complex stability analysis and regulation. Most often, this is performed by linearizing in the neighborhood of a functioning point which makes it difficult to account for changes of points e.g. for reusable launchers. In this paper the objective is to propose a non li...
Two separate experiments were conducted on a three-bladed NACA0012 rotor operating at a blade tip Reynolds number ranging from 44 − 110 × 10 3 using phase-locked infrared thermography (IRT) coupled with force and torque measurements. The first experiment consisted of a parametric study on the impact of forcing boundary layer transition using roughn...
This paper is devoted to the study of numerical methods used in the analysis of a thermal transient flight cycle. Two priorities are stressed. The first one concerns a stability issue, namely the fluid-solid interface conditions. The main properties of the Dirichlet-Robin and Neumann-Robin conditions are first recalled, before proposing for the fir...
Experiments were conducted to study the transition and flow development in a laminar separation bubble (LSB) formed on an aerofoil. The effects of a wide range of freestream turbulence intensity (0.15%
The acoustic properties of rigid porous media can be described by the equivalent fluid model (EFM) in the frequencydomain, involving complex-valued functions. These physical quantities can be irrational, which leads to fractional derivatives in thetime domain. Besides, this model is built with a constant flow resistivity, which is known to grow lin...
Avec des sécheresses en France de plus en plus courantes ou, à l'inverse, des épisodes pluvieux dont l'intensité ou la durée augmente, les exploitants sont confrontés à la gestion d'un parc de digues et barrages dont la vulnérabilité est parfois amplifiée par ces évènements. L'intensité des sollicitations hydrauliques est une première préoccupation...
In a linear input-output analysis framework, the most amplified instabilities are typically described by considering singular vectors of the resolvent operator of the linearized Navier-Stokes equations. In this study, we extend the methodology to take into account nonlinear triadic interactions by considering a finite number of harmonics in the fre...
We identify the nonlinear optimal mechanisms at the edge of the turbulent regime through solution of the frequency-domain Harmonic-Balanced Navier-Stokes equations. Specifically, we seek the optimal harmonic or multi-harmonic forcing mechanisms that maximise the skin friction coefficient asymptotically in time, which can be viewed as the minimal fo...
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