Articles techniques et présentations

High-intensity discharge lamps will in the foreseeable future be important light sources despite a growing market share of LEDs. Cost and energy efficient high frequency (300 kHz) operation is hampered by the excitation of acoustic resonances inside the arc tube, which results in low ... En savoir plus

In this paper a pre-study on using COMSOL Multiphysics for rotordynamic analysis is presented. It is concluded that it is possible to use COMSOL Multiphysics to perform rotordynamical analysis. However, there are no standard environment for rotordynamics, hence the user has to extend the ... En savoir plus

Seals or gaskets that are compressed between walls of a container are important to many industrial applications. Understanding the performance of such seals requires an understanding of the microscopic geometry of the sealing surfaces, because the fluid seeps around the undulations of ... En savoir plus

In climates with high temperature and solar radiation, reducing the cooling consumption and increasing the standards of indoor comfort are topics of great importance. The roof plays a key role in controlling the indoor thermal comfort. In ventilated roofs, air flow within the ASV (Above ... En savoir plus

Offshore wind and wave energy industries have developed considerably in the last two decades. Most offshore energy structures used in the existing projects are mono-piles in shallow water due to simplicity of installations, design and control. Numerous research for the design and ... En savoir plus

高温气冷堆中使用了大量的碳素材料，作为多孔材料，碳素材料含有一定水分等杂质。为了减小反应堆高温运行条件下的堆内材料腐蚀，高温堆在初装堆和事故后需要对一回路进行严格的加热除湿操作。目前一回路加热除湿主要是依靠主氦风机旋转，将动能转换为热能来提升温度。本文将采取另外一种方案，在蒸汽发生器处增加外加热源来加热一回路工质。基于大型商用软件COMSOL Multiphysics建立高温堆内一回路加热的流动传热模型，对两种加热方案的一回路升温过程作数值分析，为高温堆加热除湿方案的选择提供有益的指导。本文中使用的物理场为传热——共轭传热——湍流，多物理场耦合为非等温流动。 En savoir plus

Operation of a modified type microthrottle (MT) pump is analyzed by numerical simulation. Conventional MT pumps have disk type piezoelectric membranes while the analyzed type has a membrane of a rectangular shape. This could be advantageous in case the pump is stacked into an array for ... En savoir plus

This paper presents the investigation into the phenomena during batch reactor vessel mixing comparing agitation equipment; the Rushton turbine and the Marine propeller; in the production of bioethanol by yeast fermentation. The key factors addressed in selecting equipment were fluid ... En savoir plus

Our laboratory is currently leading the design and the manufacture of a novel device that allows NMR spectroscopy to be cooled down to cryogenics temperature (in the 10-100 K range). The system features a sample-holder that rotates at very high frequencies (f >10 kHz). Two aerostatics ... En savoir plus

In the emerging field of MEMS microfluidics, micropumps and microvalves are two of the most important devices with a wide spectrum of applications such as programmable drug delivery systems, lab-on-a chip devices, µTAS (micro total analysis system), micro electric cooling applications ... En savoir plus