The sizing of silencers for industrial fluids networks, whether or not involving the noise prediction of specific equipment e.g. control valves (*), safety valves (**) requires having, as available input data, indicators such as the status (choked or non-choked) of the discharge line end, the pressure at discharge line end or the discharge capacity (the flow rate) of fluid of which discharge towards atmosphere is considered.

But it not always possible to get in the context of projects involving industrial process information reflecting (accurately, completely and in an immediately interpretable form) the particular situation for which a soundproofing device is considered (or even for which a simple sound impact evaluation is wished), what is a serious obstacle to the analysis and design works to be conducted.

In some cases, data being fragmented and based on unspecified methodologies are made available, however being not suitable for sizing a silencer or pipe lagging or even for the performance of sound decay calculations in good conditions.

ITS has integrated the prediction of piping systems discharge parameters to the simulation software SILDIS (cf. acoustic simulation software).

Calculation routines have been implemented to calculate the various parameters related to the thermodynamic status of the fluid in a reservoir and to the geometry of piping system components to be considered (total pressure loss determination is a step of the computation). In some cases, additional data (sound speed, Mach number, gas velocity) can be determined in different key locations along the fluid path, such as piping system inlet, points being upstream or downstream from a valve, or at silencer entrance if any. Checking the turbulent nature of the flow (practical usual case), basing some assessments, can be performed with the software on the basis of the comparison to a reference value of the Reynolds number which is also an output data of the simulation.

Following the operations of modification of software SILDIS, comparison of simulation results with bibliographic data (measurement results, results of calculation by others, ...) showed good agreement for many combinations of those parameters which are fundamentals to properly assess a situation in terms of fluid mechanics.

The expected consequence of improvements in SILDIS software is the ability to refine the noise prediction of specific equipment e.g. industrial processes control valves (*), safety valves (**) and the sizing of depressurization silencers.

 *  SILDIS Module 8C prediction of control valves aerodynamic noise
** SILDIS Module 8D prediction of jet noise (including safety valves noise)