Articles techniques et présentations

Bloch waves in infinite periodic structures – much in vogue in the present metamaterial age – can be conveniently studied by COMSOL Multiphysics® software. This is demonstrated by a simple, yet rich two-dimensional example: a perforated sheet with square symmetry. Instead of plane waves ... En savoir plus

Airbus Safran Launchers is the market leader in Space Launch services. Rocket engines are among the most powerful machines that exist. The core of the rocket engine is the combustion chamber where in the case of liquid propellant rocket engines, fuel and oxidizer are injected, mixed and ... En savoir plus

FEM (Finite Element Method) modelling software such as COMSOL Multiphysics® can be a powerful tool for modelling the behavior and response of piezoelectric materials and devices [1]. Devices based on piezoelectric crystals are particularly well suited, because the polarization magnitude ... En savoir plus

Ultrasonic levitation is a novel technology for contactless handing of various objects. It is already used in various manufacturing processes where it is important to keep untouched surface. In this paper we introduce a model of so-called near-field ultrasonic levitation which allows ... En savoir plus

Acceleration is an important quantity to be measured in high-speed dynamics. A new piezoresistive sensor for the measurement of high-amplitude, short-duration transient accelerations of up to 100,000 g has been developed at the Fraunhofer EMI. Its figure of merit (sensitivity x resonance ... En savoir plus

In addition to using advanced functions built-into the engine of the COMSOL Multiphysics® software, we integrate dynamic properties of rotating components that are measured or pre-computed. Here, it is shown how to integrate fluid-film characteristics and take advantage of post ... En savoir plus

The acoustic scattering through a circular orifice plate in a duct with low Mach number flow (M=0.1) is computed using the Linearized Navier-Stokes physics interface of COMSOL Multiphysics®. The work by Kierkegaard et al. is extended to account for higher order acoustic modes, i.e., ... En savoir plus

Acoustic standing waves can be used to manipulate micrometer sized particles, cells and organisms. In most applications these objects are driven towards pressure nodal lines, predominantly by the primary acoustic radiation force. Interestingly, at intermediate particle concentrations, ... En savoir plus

Food dehydration processes assisted by high-power ultrasound (HPU) have become an efficient technology with a great potential in its implementation. To produce the desired effects in the samples, it is necessary that the dehydration system, composed by a HPU transducer and an ultrasonic ... En savoir plus

In this paper, the effect of a crack to the flow-induced vibration characteristics of supported pipes is investigated based on vibration method. In order to estimate the crack location and depth in the pipe, we need to utilize the variation of the difference between the natural ... En savoir plus