Shunsaku Hirayama

HVAC Blower Aeroacoustics Predictions Based on the Lattice Boltzmann Method

Two centrifugal HVAC fan and casing geometries are experimentally and numerically investigated. Aerodynamic and acoustic measurements are performed at three operating conditions following an ISO standard procedure. Explicit and compressible CFD/CAA simulations based on the Lattice Boltzmann Method are performed for six configurations. From these simulations, flow information in term of pressure rise as a function of the mass flow rate and noise are obtained at the same time and compared to experiments. Additional post-processing is performed to have an insight on the origin and location of flow-induced noise sources.Copyright

Experimental Study on Turbulent Flow and Thermal Mixing in T-Junction Modeled After Automobile HVAC Unit

This paper reports the experimental results on turbulent mixing of hot and cold airflows in a T-junction, which simulates the HVAC unit used in an automobile air conditioning system. The flow entering the main channel from the branch is separated at the edge of the T-junction and forms a large separation bubble. Longitudinal vortices are formed around this separation bubble. In spite of such a complex flow field, the mean temperature of the mixed flow shows quite uniform distributions in the spanwise direction of the channel. It has been also found that the strong turbulence produced around the separation bubble does not contribute effectively to the thermal mixing of hot and cold airflows.Copyright