Abstract
In order to reduce the fan power of a 4-way cassette type indoor unit of a packaged air conditioner, we developed the shape of air outlet nozzles reducing of the pressure-loss. The main cause of the pressure-loss was the flow separation area shaped in current air outlet nozzles. Therefore, we devised the shape for the control of the flow separation area. The shape was defined by two parameters, and the influence of parameters on the fan power reduction was surveyed by using the simulation technology with CFD (Computational Fluid Dynamics). We used the response surface which was made by results of CFD and approximate values with the Kriging-based method since the appropriate combination of parameters was efficiently searched from multiple parameters. As the result, the combination of parameters which reduces the fan power the most in the response surface was found. The shape adopted the combination of parameters can control the flow separation area. The fan power reduction by 9.9% in comparison with the current shape of air outlet nozzles was confirmed by the experiment.
