Publications related to Supersonic aircraft

Crack front waves: A 3D dynamic response to a local perturbation of tensile and shear cracks

Jean-François Molinari, Fabian Barras, Damien Spielmann, Fatima-Ezzahra Fekak

Crack front waves are long-lived perturbations propagating along the crack front. They are triggered by heterogeneities on the crack plane, as for instance tough asperities, which disturb the crack front shape. Crack front waves are thought to leave a trac ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Comparative study between Cubic and Ellipsoidal Fokker-Planck kinetic models

Mohammadhossein Gorji

Motivated by improving the performance of particle-based Monte-Carlo simulations in the transitional regime, Fokker–Planck kinetic models have been devised and studied as approximations of the Boltzmann collision operator. By generalizing the linear drift ...

2019

Measurements of ion velocity and wave propagation in a hollow cathode plume

The mechanism responsible for the production of energetic ions in the plume of hollow cathodes for electric propulsion is still an open issue. These ions are of concern to cathode and thruster lifetime, particularly for cathodes operating at high (>20 A) d ...

IOP PUBLISHING LTD2019

Two-fluid plasma model for radial Langmuir probes as a converging nozzle with sonic choked flow, and sonic passage to supersonic flow

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne

Using the Lambert function, Guittienne et al. [Phys. Plasmas 25, 093519 (2018)] derived two-fluid solutions for radial Langmuir probes in collisionless and isothermal plasma. In this Brief Communication, we point out the close analogy with classical compre ...

American Institute of Physics (AIP)2019

The microfluidic nebulator: production of submicrometer sized airborne drops

Esther Amstad

Many powders employed in the food and pharmaceutical industries are produced through spray drying because it is a cost efficient process that offers control over the particle size. However, most commercially available spray-driers cannot produce drops with ...

Royal Soc Chemistry2017

Wave propagation in periodic buckled beams. Part I: Analytical models and numerical simulations

Alessandro Spadoni, Florian Paul Robert Maurin

Periodic buckled beams possess a geometrically nonlinear, load-deformation relationship and intrinsic length scales such that stable, nonlinear waves are possible. Modeling buckled beams as a chain of masses and nonlinear springs which account for transver ...

Elsevier Science Bv2016

Impact of rotating and fixed nozzles on vortex breakdown in compressible swirling jet flows

François Gallaire, Leonhard Kleiser

Vortex breakdown of swirling, round jet flows is investigated in the compressible, subsonic regime by means of Direct Numerical Simulation (DNS). This is achieved by solving the compressible Navier-Stokes equations on a cylindrical grid using high-order sp ...

Elsevier2016

Quantifying the Bullwhip Effect Using Two-Echelon Data: A Cross-Industry Empirical Investigation

Ralf Seifert, Olov Isaksson

The bullwhip effect denotes the phenomenon whereby demand variability is amplified from a downstream site (buyer) to an upstream site (supplier) in the supply chain. This paper contributes to the literature that empirically investigates the bullwhip effect ...

Elsevier2016

NANOPARTICLES Production of amorphous nanoparticles by supersonic spray-drying with a microfluidic nebulator

Esther Amstad

Amorphous nanoparticles (a-NPs) have physicochemical properties distinctly different from those of the corresponding bulk crystals; for example, their solubility is much higher. However, many materials have a high propensity to crystallize and are difficul ...

American Association for the Advancement of Science2015

Evolution of the Aerodynamic Stability of an Oscillating Annular Compressor Cascade with Inlet Reverse Flow Condition Variations

Peter Ott, Virginie Anne Chenaux

While the advancement of computing hardware now enables accurate predictions of flutter and forced response at normal flow conditions during the compressor design phase, aeroelastic computations at off-design or reverse flow conditions remain a challenging ...

Lappeenranta University of Technology2013

Characterization of the Flow Generated in an Annular Test Facility

Peter Ott, Elia Colombo, Dominique Charbonnier, Cécile Deslot

Annular cascades are particularly useful to study the three dimensional phenomena encountered in turbomachines. The Non-Rotating Annular Test Facility of the Swiss Federal Institute of Technology in Lausanne (EPFL) consists in a radial-axial inlet nozzle a ...

2011

On the use of anisotropic a posteriori error estimators for the adaptative solution of 3D inviscid compressible flows

Marco Picasso

This paper describes the use of an a posteriori error estimator to control anisotropic mesh adaptation for computing inviscid compressible flows. The a posteriori error estimator and the coupling strategy with an anisotropic remesher are first introduced. ...

2009

Interaction between a surface dielectric barrier discharge and transonic airflows

Samantha Pavon

The use of plasmas in aerodynamics has become a recent topic of interest. The potentialities of different types of plasmas are being investigated for low velocity and high velocity flow control, as well as for plasma-assisted combustion. Dielectric barrier ...

EPFL2008

Inclusion of aerodynamic non-equilibrium effects in supersonic plasma jet enthalpy probe measurements

Christoph Hollenstein, Malko Gindrat

Low pressure plasma spraying (LPPS) is a thermal spraying technique that has found a niche for low oxidation products. It uses a low pressure environment (i.e:, chamber pressure between 2 and 90 kPa) and yields supersonic plasma jets. The enthalpy probe te ...

2005

Characterization of supersonic low pressure plasma jets

Malko Gindrat

Low Pressure Plasma Spraying (LPPS) processes use a DC plasma jet expanding at low pressure for fast deposition of dense coatings in a controlled atmosphere. The LPPS technology is widely used industrially in particular in the aeronautics and medical indus ...

EPFL2004