A method for determining a mass flow of a dynamic compressor that does not include a mass flow sensor while the compressor is operating to compress a working fluid includes determining, by a processor, a current operating point of the compressor. If the current operating point is the same as one in a map of a plurality of predetermined operating points stored in a memory, the mass flow of that predetermined operating point is retrieved as the mass flow of the current operating point. Otherwise, the processor calculates the mass flow at the current operating point from the mass flows of a subset of the predetermined operating points nearest the current operating point. The dynamic compressor continues to operate to compress the working fluid based at least in part on the calculated mass flow rate for the current operating point.

A method for determining a mass flow of a dynamic compressor that does not include a mass flow sensor while the compressor is operating to compress a working fluid includes determining, by a processor, a current operating point of the compressor. If the current operating point is the same as one in a map of a plurality of predetermined operating points stored in a memory, the mass flow of that predetermined operating point is retrieved as the mass flow of the current operating point. Otherwise, the processor calculates the mass flow at the current operating point from the mass flows of a subset of the predetermined operating points nearest the current operating point. The dynamic compressor continues to operate to compress the working fluid based at least in part on the calculated mass flow rate for the current operating point.

The present invention relates to a blower. A blower according to an embodiment of the present invention comprises: a lower case having a suction hole in through which air flow; an upper case which is disposed at the upper side of the lower case and which has a discharge port through which the air is discharged; a fan motor for providing rotating force; and a fan disposed inside the lower case and fixed to a motor shaft of the fan motor, wherein the fan includes: a hub having an outer surface, which is extended to be inclined at a first angle with respect to the motor shaft; a plurality of blades coupled to the hub; and a shroud having an inner surface which is extended to be inclined, with respect to the motor shaft, at a second angle that is greater than the first angle, and which faces the outer surface of the hub with respect to the blade, and thus the air discharged from the fan can change into an ascending current.

A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

A method of making an impeller includes building the impeller in a layer by layer process in a build direction along the rotational axis starting from a base of the hub. The plurality of blades includes a plurality of perforated blades that support the shroud during additively manufacturing the impeller. The method can include installing the impeller in a fuel pump, air compressor, or the like, without removing the perforated blades from the impeller.

A variable height fan of an information handling system includes a first fan having a first hub and a first plurality of fan blades. A second fan impeller includes a second hub and a second plurality of fan blades. The first hub slides along the second hub as the variable height fan transitions between an expanded position and a collapsed position. Interior edges of the first hub are in physical communication with exterior edges of the second hub, and the second fan impeller drives the first fan impeller through the physical communication between the interior edges of the first hub and the exterior edges of the second hub.

A cross-flow fan, and blades of a cross-flow fan are provided. The cross-flow fan includes a rotary shaft; a plurality of blades that extends in a direction parallel to the rotary shaft and having a positive pressure surface and a negative pressure surface; and a connector that connects the rotary shaft and the plurality of blades. At least one protrusion that protrudes in a thickness direction and extends in a longitudinal direction of the plurality of blades is formed on the plurality of blades, and by means of the at least one protrusion formed on a blade surface, a flow separation phenomenon caused by friction with the blade surface is suppressed, thereby reducing noise generated by the cross-flow fan.

A cross-flow fan, and blades of a cross-flow fan are provided. The cross-flow fan includes a rotary shaft; a plurality of blades that extends in a direction parallel to the rotary shaft and having a positive pressure surface and a negative pressure surface; and a connector that connects the rotary shaft and the plurality of blades. At least one protrusion that protrudes in a thickness direction and extends in a longitudinal direction of the plurality of blades is formed on the plurality of blades, and by means of the at least one protrusion formed on a blade surface, a flow separation phenomenon caused by friction with the blade surface is suppressed, thereby reducing noise generated by the cross-flow fan.

Proposed is an impeller-type exhaust apparatus for blocking transfer of heat including a first disc facing a high-temperature gas, a second disc spaced apart from the first disc to form a heat blocking space, a plurality of blades formed along the circumferences of the first disc and the second disc, and a motor which provides rotary power to the first disc and the second disc, wherein heat can be blocked through the heat blocking space.