摘要:
A counter-rotating axial flow fan with improved characteristics and reduced noise compared to the related art can be provided. Defining the number of front blades as N, the number of stationary blades as M, and the number of rear blades as P, and defining the maximum axial chord length of the front blades as Lf, the maximum axial chord length of the rear blades as Lr, the outside diameter of the front blades as Rf, and the outside diameter of the rear blades as Rr, the counter-rotating axial flow fan satisfies the following two relationships: N≧P>M; and Lf/(Rf×π/N)≧1.25 and/or Lr/(Rr×π/P)≧0.83.
摘要:
A counter-rotating axial flow fan in which the shape of stationary blades of a middle stationary portion is optimized to reduce noise is provided. Defining the maximum axial chord length of front blades as Lf, the maximum axial chord length of rear blades as Lr, and the maximum axial chord length of stationary blades as Lm, a relationship of Lm/(Lf+Lr) 5.8.
摘要:
A counter-rotating axial flow fan with reduced noise at the target operating point achieved without modifying a front impeller, a rear impeller, or a middle stationary portion is provided. An annular rib including a projecting surface for generating turbulent flow is formed on an inner wall portion of a casing at a position off from the middle stationary portion to a side of the rear impeller, the projecting surface extending radially inwardly of the inner wall portion and extending continuously in the circumferential direction of the inner wall portion. A fluid striking the projecting surface for generating turbulent flow is partially disturbed to form a turbulent flow before entering an area in which the rear impeller is provided. The turbulent flow suppresses flow separation of a fluid flowing along the surfaces of rear blades of the rear impeller from the surfaces of the rear blades.
摘要:
A vaporizing type liquid fuel combustion apparatus comprising a pot burner, vaporizer for vaporizing liquid fuel provided above the pot burner, a fuel supply pipe for supplying the liquid fuel to the vaporizer, a vaporized gas combustion burner which has a gas chamber connected to the vaporizer and which is arranged to heat the vaporizer, and a blower for supplying air to the pot burner and the vaporized gas combustion burner.
摘要:
A sound-volume prediction apparatus acquires model information on an electronic device and positional information on an air intake section and/or an air-exhaust section of the electronic device. Furthermore, by using the model information and the positional information, the sound-volume prediction apparatus extends a sound ray that indicates a transmission route of sound generated by a sound source inside the electronic device toward the air-intake section and/or the air-exhaust section from the position of the sound source until the sound ray reaches the outside of the electronic device. The sound-volume prediction apparatus predicts sound transmission characteristics inside the electronic device by using geometric information on the flow path of the extended sound ray.
摘要:
A counter-rotating axial flow fan with reduced noise at the target operating point achieved without modifying a front impeller, a rear impeller, or a middle stationary portion is provided. An annular rib including a projecting surface for generating turbulent flow is formed on an inner wall portion of a casing at a position off from the middle stationary portion to a side of the rear impeller, the projecting surface extending radially inwardly of the inner wall portion and extending continuously in the circumferential direction of the inner wall portion. A fluid striking the projecting surface for generating turbulent flow is partially disturbed to form a turbulent flow before entering an area in which the rear impeller is provided. The turbulent flow suppresses flow separation of a fluid flowing along the surfaces of rear blades of the rear impeller from the surfaces of the rear blades.
摘要:
A plasma display panel includes at least one pair of discharge electrodes disposed on a substrate, a drive circuit for applying a discharge voltage to the discharge electrodes, capacity elements for raising voltage connected in series between the discharge electrodes and the drive circuit, and a control circuit for generating discharge across the discharge electrodes. The control circuit applies a charging voltage to the capacity elements for raising voltage and thereafter applies the discharge voltage from the drive circuit to the discharge electrodes via the capacity elements for raising voltage.
摘要:
A sound-volume prediction apparatus acquires model information on an electronic device and positional information on an air intake section and/or an air-exhaust section of the electronic device. Furthermore, by using the model information and the positional information, the sound-volume prediction apparatus extends a sound ray that indicates a transmission route of sound generated by a sound source inside the electronic device toward the air-intake section and/or the air-exhaust section from the position of the sound source until the sound ray reaches the outside of the electronic device. The sound-volume prediction apparatus predicts sound transmission characteristics inside the electronic device by using geometric information on the flow path of the extended sound ray.
摘要:
An axial blower includes a moving vane generating air flow by rotation, a casing accommodating said moving vane, and an adapter detachably attached to the casing. The adapter includes a fitting part to be fit to an inner surface of the casing. The adapter forms a protrusion or a step on the inner surface of the casing.
摘要:
A counter-rotating axial flow fan in which the shape of stationary blades of a middle stationary portion is optimized to reduce noise is provided. Defining the maximum axial chord length of front blades as Lf, the maximum axial chord length of rear blades as Lr, and the maximum axial chord length of stationary blades as Lm, a relationship of Lm/(Lf+Lr) 5.8.