摘要:
A fluid flow probe including: first, second and third pressure sensors; a first port for communicating a first pressure to the first pressure sensor; a second port for communicating a second pressure to the second pressure sensor, the second port being substantially oppositely disposed with respect to the first port, a third pressure port suitable for communicating a static pressure to the third pressure sensor; first and second outputs electrically coupled to the first and second pressure sensors, respectively, one of the first and second outputs indicative of a total pressure and the other of the outputs indicative of a base pressure; and, a third output electrically coupled to the third pressure sensor and indicative of the static pressure.
摘要:
A fluid flow probe including: first, second and third pressure sensors; a first port for communicating a first pressure to the first pressure sensor; a second port for communicating a second pressure to the second pressure sensor, the second port being substantially oppositely disposed with respect to the first port, a third pressure port suitable for communicating a static pressure to the third pressure sensor; first and second outputs electrically coupled to the first and second pressure sensors, respectively, one of the first and second outputs indicative of a total pressure and the other of the outputs indicative of a base pressure; and, a third output electrically coupled to the third pressure sensor and indicative of the static pressure.
摘要:
A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure.
摘要:
A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing.
摘要:
A transducer comprising a filter assembly that measures low amplitude, dynamic pressure perturbations superimposed on top of a high static pressure through the implementation of a low-pass mechanical filter assembly. The filter assembly may comprise a dual lumen reference tube and a removable filter subassembly further comprising a porous metal filter and narrow diameter tube. The transducer, which may be capable of operating at ultra-high temperatures and in harsh environments, may comprise of a static piezoresistive pressure sensor, which measures the large pressures on the order of 200 psi and greater, and an ultrasensitive, dynamic piezoresistive pressure sensor which may capture small, high frequency pressure oscillations on the order of a few psi. The filter assembly may transmit static pressure to the back of the dynamic pressure sensor to cancel out the static pressure present at the front of the sensor while removing dynamic pressure.
摘要:
It is an objective of the present invention to provide a pressure transducer assembly for measuring pressures in high temperature environments that employs an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation.
摘要:
A filter assembly for use with a static-dynamic piezoresistive pressure transducer that measures low amplitude, dynamic pressure perturbations superimposed on top of a high static pressure through the implementation of a low-pass mechanical filter assembly is disclosed. The filter assembly may comprise a dual lumen reference tube and a removable filter subassembly further comprising a porous metal filter and narrow diameter tube. The transducer, which may be capable of operating at ultra-high temperatures and in harsh environments, may comprise of a static piezoresistive pressure sensor, which measures the large pressures on the order of 200 psi and greater, and an ultrasensitive, dynamic piezoresistive pressure sensor which may capture small, high frequency pressure oscillations on the order of a few psi or less. The filter assembly may transmit static pressure to the back of the dynamic pressure sensor to cancel out the static pressure present at the front of the sensor while keeping dynamic pressure from reaching the back of the sensor. In this manner, the filter assembly enables the transducer to accurately read dynamic pressure in the presence of high static pressure without rupturing the thin diaphragm of the dynamic pressure sensor.
摘要:
A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing.
摘要:
A system for sensing at least one physical characteristic associated with an engine including a turbine having a plurality of blades turning inside a casing, the system including: a pressure sensor coupled substantially adjacent to the casing and including at least one output; a port in the turbine casing for communicating a pressure indicative of a clearance between the blades and casing to the pressure sensor; a cooling cavity substantially surrounding the pressure sensor; and, an inlet for receiving fluid from the engine and feeding the fluid to the cooling cavity to cool the pressure sensor; wherein, the pressure sensor output is indicative of the clearance between the blades and casing.
摘要:
A pressure transducer for measuring pressures in high temperature environments employs a tube which is terminated at one end by an acoustic micro-filter. The acoustic filter or micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. Mounted to the tube is a pressure transducer with a diaphragm flush with the inner wall of the tube. The tube is mounted in an aperture in a casing of a gas turbine operating at a high temperature. The hot gases propagate through the tube where the pressure of the gases are measured by the transducer coupled to the tube and where the acoustic filter operates to absorb acoustic waves impinging on it with little or no reflection, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation.