Challenge and Opportunities for Flow Noise Prediction in HVAC Systems

G1 - Installation Effect

This paper investigates the possibilities of semi empirical scaling laws for noise prediction in Heating Ventilation and Air Conditioning (HVAC) systems. Semi empirical scaling laws are an option for noise predictions to avoid a time consuming fully resolved simulation. The scaling laws can be seen as a combination of generalized noise measurement data and component flow characteristics, where the latter can be gained from Computational Fluid Dynamics (CFD) simulations of low complexity. An approach is here presented where the general noise reference spectra are combined with Reynolds Average Navier Stokes (RANS) simulations. To evaluate which HVAC geometries that can be included in a general model, both literature data and new measurement data are included. Focus is at applying the suggested noise prediction approach to common HVAC components but also to discuss the differences in other properties, e.g. radiation characteristics. Air terminal devices at the end of a duct will be compared to in duct components and silencers with baffles of different length will be evaluated. A model is concluded using a momentum flux assumption of the noise sources enabling a range of HVAC system components to be included. Since flow generated noise from non-rotating components is becoming more important in HVAC systems, the suggested approach is seen as a promising tool for noise prediction of HVAC components.