Abstract: A cooling device for a vehicle may include a heat exchanger provided to cool an engine of the vehicle, a radiator provided near a side of and in parallel with the heat exchanger to cool an inside of the vehicle, and a cooling fan provided near a side of the radiator to coercively introduce external air into the heat exchanger and the radiator, wherein the cooling fan includes a hub connected to a driving shaft, and a plurality of blades radially arranged on an outer circumferential surface of the hub, wherein the plurality of blades are arranged so that a spaced area between two neighboring blades is different from a spaced area between other two neighboring blades, and wherein a sum of all vectors for the plurality of blades is not zero, the vector being reached from the center of the hub to a reference point of each blade.

Abstract: The present invention relates generally to a method of visualizing the sound fields of sound sources using acoustic holography, which discriminates the sound fields of individual sound sources having the same frequency component and visualizes the sound fields thereof. In the method, sound pressures are calculated on a sound source plane using sound pressures measured on a hologram plane. A single sound source having a position of a maximum sound pressure on the sound source plane is extracted, and a value of the sound pressure at the position is evaluated as a signal coherent to the sound source. A sound field of the extracted sound source is obtained using the coherent signal. The sound field is eliminated from sound fields of all sound sources, and it is determined whether any remaining sound field exists. The process returns to the sound field obtaining operation if any remaining sound field exists.

Abstract: The present invention relates generally to a method of visualizing the sound fields of sound sources using acoustic holography, and more particularly to a method, which discriminates the sound fields of individual sound sources having the same frequency component and visualizes the sound fields thereof.