Turbo machines

Gas Turbine Enclosure Ventilation

Context

A gas turbine enclosure has a triple function: to ensure noise containment, to cool all parts and also to secure the entire system in the event of an accidental leak of flammable gas. In the case of minor explosions, the ventilation of the enclosure must allow gas leaks to be detected thanks to the correct positioning of sensors.

Resolution

This type of study involves analyzing the ventilation system to determine stagnant zones, and modeling gas leaks in these zones across multiple scenarios. A multi-species analysis can then be used to determine the gas mixtures inside the acoustic enclosure.

Results

This type of study allows the stratification of the flammable gas mixture to be calculated for multiple leak scenarios. And also to define the optimal positions of the gas sensors and their detection levels for the triggering of alarms.

Homogeneity of Power Supply and Compressor Acoustics

Context

Compressors are acoustic sources of structure-borne and airborne noise, particularly due to the speeds involved and the shear layers. Compressor acoustics remains a crucial issue in compressor operation.

Resolution

Starting from a full-360° modelof the first compressor stage (stator and rotor), it is possible to have the main acoustic source of a compressor. The numerical model is based on a correct apprehension of the boundary layers in walls and on an unsteady resolution with a precise temporal sampling.

Results

The positioning of acoustic sensors made it possible to calculate the sound pressure and determine the best flow distribution in order to reduce the aeroacoustic noise of the compressor.

Sizing of a Fan

Context

Bladed fans are frequently used in industry to cool components or complete systems. In particular, they are used in rotating machines by taking advantage of the axis of rotation of the electro-technical machine for its self-ventilation.

Resolution

In order to achieve the required ventilation performance and correct cooling of the rotating machine, several blade optimizations were necessary to improve the aerodynamic efficiency of the blades. Carried out on an angular sector, the optimizations were quickly carried out so as not to impact the project schedule.