초록 ▼

A temperature sensor is provided with at least two thermometers or temperature sensing elements that have different recovery factors, and which are in the same airflow. The recovery factors for the respective thermometers are determined for the sensor and stored in a memory of a processor. The tempe

A temperature sensor is provided with at least two thermometers or temperature sensing elements that have different recovery factors, and which are in the same airflow. The recovery factors for the respective thermometers are determined for the sensor and stored in a memory of a processor. The temperature measured by each of the thermometers is provided to the processor, and the processor establishes ratios using the recovery factors and measured temperatures to determine total temperature and static temperature of the airflow in which the thermometers are placed.

대표청구항 ▼

What is claimed is: 1. A temperature sensing assembly comprising a support having at least two thermometers mounted on the support, the thermometers being mounted to have different and known recovery factors when supported in common airflow, and circuitry providing signals indicating temperatures s

What is claimed is: 1. A temperature sensing assembly comprising a support having at least two thermometers mounted on the support, the thermometers being mounted to have different and known recovery factors when supported in common airflow, and circuitry providing signals indicating temperatures sensed at each of the thermometers, and the circuitry receiving signals representing the recovery factors of the thermometers, and being operable to calculate at least one of static temperature and total temperature of the airflow, based on the recovery factors and sensed temperatures of the two thermometers. 2. The temperature sensing assembly of claim 1 wherein the support comprises a housing having flow paths for directing airflow, said flow paths being of different configurations from each other, and a first of the thermometers mounted a first flow path, and a second of the thermometers mounted in a second flow path. 3. The temperature sensing assembly of claim 1 wherein said thermometers comprise resistance temperature sensing elements. 4. The temperature sensing assembly of claim 1, and a processor comprising the circuitry, the recovery factors of each of the thermometers being accessible to the processor, said processor receiving signals indicating measured temperature at each of the thermometers, and the processor establishing the ratios: description="In-line Formulae" end="lead"Rf 1=(Tr1-Ts)/(Tt-Ts) anddescription="In-line Formulae" end="tail" description="In-line Formulae" end="lead"Rf 2=(Tr2Ts)/(Tt-Ts)description="In-line Formulae" end="tail" where Rf1 is the recovery factor of the first thermometer, and Rf2 is the recovery factor of the second thermometer, Tr1 and Tr2 are the measured temperatures at the first and second thermometers, respectively, Tt is total temperature, Ts is static temperature, and wherein the processor solves for the values Tt and Ts. 5. The temperature sensing assembly of claim 1 wherein said support comprises an upstream edge wall, a pair of recesses having upstream ends and downstream ends, each of the recesses having a wall surface at an upstream end extending inwardly from an outer end of the upstream edge wall, and the recesses being defined by bottom surfaces that join inner ends of the respective wall surfaces and incline outwardly in the downstream direction, the bottom surfaces having different inclinations from each other. 6. The temperature sensing assembly of claim 5, wherein said outwardly inclined bottom surfaces comprise generally planar surfaces that taper from the inner edges of the respective upstream wall surfaces to an outer surface of the support at different angles relative to the outer surface. 7. The temperature sensing assembly of claim 5, wherein the support contains both recesses, the bottom surfaces of the respective recesses being generally planar and at different angular orientations with respect to a planar bottom mounting surface of the support. 8. The temperature sensing assembly of claim 1, wherein said support has an upstream end and a downstream end, upwardly facing surfaces of the support having configurations that differ from one another in each of at least two sections, at least one of the thermometers being mounted in each of said sections, the differing configurations causing different recovery factors of the respective thermometers on the support as air flows over the upwardly facing surfaces of the support. 9. The temperature sensing assembly of claim 8, wherein the upwardly facing surface on one of the sections is concave, and the upwardly facing surface on the other section is convex. 10. The temperature sensing assembly of claim 8, wherein the upwardly facing surfaces on both sections are concave, the concavities being the deepest adjacent an upstream end of the support. 11. The temperature sensing assembly of claim 1, wherein said support comprises a housing extending outwardly from a supporting surface into a common airflow, said housing having a plurality of passageways, including a first passageway facing in a direction of airflow and providing an inlet scoop, an outlet from said first passageway, a flow separation bend in the housing at a side of the first passageway to divert a portion of the airflow from the first passageway to at least one other passageway formed in portions of the housing other than the portion having the first passageway, and an outlet opening for airflow from the at least one other passageway, the thermometers being mounted in the other portions of the housing and positioned so that each of the thermometers has a different volume of air flowing past the respective thermometer to thereby provide a recovery factor for each thermometer different from each of the other thermometers relative to free stream conditions of the airflow. 12. The temperature sensing assembly of claim 1, wherein said support comprises a housing extending outwardly from a supporting surface, said housing having a plurality of passageways therein, including a first passageway facing in a direction of airflow and providing an inlet scoop at an upstream end, an outlet from said first passageway at a downstream end thereof, a flow separation bend in the housing at a side of the first passageway, a laterally extending second passageway open to the first passageway downstream of the flow separation bend, an exit opening from said laterally extending second passageway, the at least two thermometers comprising first and second thermometers mounted in said laterally extending second passageway at positions such that the second thermometer has a different recovery factor from the first thermometer as air flows past the thermometers. 13. The temperature sensing assembly of claim 12, further characterized by a third thermometer mounted in said laterally extending second passageway. 14. The temperature sensing assembly of claim 13, wherein the thermometers provide signals Tr1, Tr2, and Tr3 indicating temperatures measured by the respective first, second, and third thermometers as airflow velocity changes, and a circuit to receive the signals indicating Tr1, Tr2, Tr3, and to provide a ratio (Tr1-Tr2)/(Tr1-Tr3). 15. A method of determining total temperature and static temperature using sensed temperatures comprising providing two separated thermometers supported relative to a common airflow; determining the recovery factors of each of the thermometers as supported relative to the airflow; measuring the temperature sensed by each of the thermometers; establishing ratios utilizing the recovery factors of the respective thermometers, and the measured temperature at each of the thermometers to solve for total temperature and static temperature of the common airflow. 16. The method of claim 15, wherein establishing ratios comprises establishing the ratios: description="In-line Formulae" end="lead"Rf1 =(Tr1-Ts)/(Tt-Ts);description="In-line Formulae" end="tail" description="In-line Formulae" end="lead"Rf2 =(Tr2-Ts)/(Tt-Ts)description="In-line Formulae" end="tail" where Rf1 and Rf2 are the recovery factors of the respective thermometers, Tr and Tr2 are the measured temperatures at the respective thermometers, Tt is total temperature and Ts is static temperature of the airflow. 17. The method of claim 16 including providing a third thermometer having a third different recovery factor, and establishing a ratio of the differences of measured temperatures at the three thermometers comprising (Tr1-Tr2)/(Tr1-Tr 3), to establish a factor unique to Mach number, where Tr1, Tr2, and Tr3 are the temperatures measured by the thermometers. 18. The method of claim 15 including further calculating at least one of Mach number and true airspeed after solving for at least one of total temperature and static temperature of the air flow. 19. The method of claim 18, wherein the further calculating of at least one of Mach number and true airspeed comprises using one of the equations: description="In-line Formulae" end="lead"T total/Tstatic=1+0.2M2description="In-line Formulae" end="tail" Where Ttotal is total temperature and Tstatic is static temperature, and description="In-line Formulae" end="lead"V true=Mc=M(1.4RTstatic)0.5description="In-line Formulae" end="tail" Where Vtrue is true airspeed, M is Mach number, c is the speed of sound and R is the gas constant for air. Tstatic is expressed as an absolute temperature. 20. A temperature sensing assembly for determining air data parameters of air flowing past the assembly, comprising a housing having at least two thermometers mounted on the housing in positions to receive a common air flow, the thermometers having different and known recovery factors (Rf) when supported on the housing in the air flow, the thermometers each providing signals indicating temperatures sensed thereby, and a processor receiving the signals and providing ratios based on the sensed temperatures and recovery factors of the thermometers to provide outputs representing total temperature and static temperature. 21. The temperature sensing assembly of claim 20, wherein the processor establishes the ratios: description="In-line Formulae" end="lead"Rf 1=(Tr1-Ts)/(Tt-Ts) anddescription="In-line Formulae" end="tail" description="In-line Formulae" end="lead"Rf 2=(Tr2-Ts)/(Tt-Ts)description="In-line Formulae" end="tail" where Rf1 is the recovery factor of a first thermometer, and Rf2 is the recovery factor of a second thermometer, Tr1 and Tr2 are the measured temperatures at the first and second thermometers, respectively, Tt is total temperature, Ts is static temperature, and wherein the processor solves for the values Tt and Ts. 22. The temperature sensing assembly of claim 21, wherein said housing has an upstream edge wall, first and second sections formed on the housing having upstream ends and downstream ends, each of the sections having a wall surface over which air flows from the upstream end to the downstream end, the respective wall surfaces of the first and second sections being configured to have different effects on the airflow, and wherein the first and second thermometers are on different sections of the housing. 23. The temperature sensing assembly of claim 22, wherein the wall surface of the first section is recessed and concave, and the wall surface of the second section is convex. 24. The temperature sensing assembly of claim 20, and a source of a signal indicating at least one of the group consisting of measured total pressure and static pressure provided to the processor, the processor providing outputs indicating additional desired air data parameters, including at least one of Mach number, true airspeed, total pressure and static pressure.