Publications related to De Laval nozzle

Numerical analysis of apparatus-induced dispersion for density-dependent solute transport in porous media

The effects of apparatus-induced dispersion on nonuniform, density-dependent flow in a cylindrical soil column were investigated using a finite-element model. To validate the model, the results with an analytical solution and laboratory column test data we ...

2023

Cavitation bubble dynamics and microjet atomization near tissue-mimicking materials

Mohamed Farhat, Davide Bernardo Preso, Armand Baptiste Sieber

In recent years, considerable interest has been devoted to the interactions between cavitation bubbles and tissue-mimicking materials due to their promising applications in medicine and biomedical sciences. The strong fluid-structure interaction between a ...

AIP Publishing2023

Control of intermetallics in the interface in directed energy deposition of titanium on stainless steel 316L

Di Cui

Application of a single metal or alloy is often restricted by its properties from optimal combination of performance and cost. Therefore, there is a vast need of joining dissimilar metals for various applications in biomedical, aerospace, automobile and ma ...

EPFL2023

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

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

Rapid Production of Submicron Drug Substance Particles by Supersonic Spray Drying

Esther Amstad

Many newly developed active pharmaceutical ingredients (APIs) are poorly soluble in water and thus have a dissolution-limited bioavailability. The bioavailability of Biopharmaceutical Classification System (BCS) class II APIs increases if they dissolve fas ...

Amer Chemical Soc2017

A Continuation Multi Level Monte Carlo (C-MLMC) method for uncertainty quantification in compressible inviscid aerodynamics

Fabio Nobile, Pénélope Leyland, Michele Pisaroni

In this work we apply the Continuation Multi-Level Monte Carlo (C-MLMC) algorithm proposed in Collier et al. (2014) to efficiently propagate operating and geometric uncertainties in inviscid compressible aerodynamics numerical simulations. The key idea of ...

Elsevier2017

Fluid flow through replicated microcellular materials in the Darcy-Forchheimer regime

Andreas Mortensen, Ludger Weber, David Ingram, Alexandros Athanasiou-Ioannou, Sandra Guardia

We extend here a “bottleneck” flow model derived earlier for incompressible fluids flowing under creeping flow conditions [Despois, J. and Mortensen, A: Acta Materialia 53 (2005) 1381] to flow regimes where inertial losses are no longer negligible, causing ...

Elsevier2017

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

Applications of Model Reduction Techniques in Aerospace Combustors

Jan Sickmann Hesthaven

In this paper we consider some practical applications of model reduction methods in unstable gas turbine and rocket combustion. We explore a set of promising methods for reducing computational burden in large scale LES calculations of unsteady turbulent co ...

2014

Fluid-Structure Coupling Effects on the Dynamic Response of Pump-Turbine Guide Vanes

Steven Roth

Hydraulic pump-turbines are subject to a high periodic excitation due to the Rotor-Stator Interaction, RSI. Basically, the RSI is caused by the impeller blade passage in the wake of the guide vanes in generating mode, or upstream from the guide vanes in pu ...

EPFL2012

Material and velocity effects on cavitation erosion pitting

Ayat Karimi, Jean-Pierre Franc

Cavitation erosion during the incubation period was investigated via pitting tests conducted on three different materials: an Aluminum alloy, a Nickel Aluminum Bronze alloy and a Duplex Stainless Steel. Pitting tests were conducted in a cavitation tunnel i ...

2012

Control of axisymmetric vortex breakdown in a constricted pipe: Nonlinear steady states and weakly nonlinear asymptotic expansions

François Gallaire, Philippe Meliga

The present paper investigates numerically and theoretically the axisymmetric vortex breakdown occurring in a constricted pipe of infinite extension, i.e., the transition from a smooth columnar state to a breakdown state exhibiting a recirculation bubble. ...

2011

Investigation on the Three-Dimensional Flow Mechanisms in Annular Axial Compressor Cascades for Aero Engines with Flow Control by Aspiration on the Hub and on the Blades

Elia Colombo

The axial compressor is an essential component of aero-engines and gas turbines. This work investigates how flow control by aspiration applied to the hub and to the blades of axial compressor wheels can improve the static pressure rise by preventing detrim ...

EPFL2011

Fabrication of microfluidic mixers with varying topography in glass using the powder blasting process

Martinus Gijs, Abdeljalil Sayah, Virendra Kumar Parashar

The powder-blasting method is used to fabricate structures with a three-dimensional topography in glass using elastomeric masks. The relation between the mask opening width and the erosion depth is exploited to fabricate microstructures with varying depth ...

2009

Experimental Evidence of Hydroacoustic Pressure Waves in a Francis Turbine Elbow Draft Tube for Low Discharge Conditions

François Avellan, Christophe Nicolet

The complex three-dimensional unsteady flow developing in the draft tube of a Francis turbine is responsible for pressure fluctuations, which could prevent the whole hydropower plant from operating safely. Indeed, the Francis draft tube is subjected to inl ...

2009

The gas flow rate increase obtained by an oscillating piezoelectric actuator on a micronozzle

Jürgen Brugger

Micronozzles with piezoelectric actuator were fabricated and investigated. The micronozzles were fabricated in glass substrates using a powderblasting technique, and the actuator is a bimorph structure made from a piezoelectric polymer. The actuator was lo ...

2008

Highly loaded compressor with boundary layer suction

Klaus Hubrich

An experimental and numerical investigation of boundary layer suction (BLS) on a transonic compressor blade has been conducted. The objective of the present work is to identify the possible benefit of boundary layer suction via a slot in the region of the ...

EPFL2005