Patent US3837220A successfully refreshed from Google Patents.
US3837220A
Expired / Lapsed
US
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Determination of gross thrust-related parameters
Assignee: General Dynamics Canada Ltd
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Filing: 1972-10-27
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Granted: 1974-09-24
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Expires: 1992-10-27
Abstract
Abstract It is known to obtain a correction factor by determining theoretical gross thrust by measuring engine pressures and by measuring actual gross thrust and using a comparison between theoretical and measured gross thrust to develop a correction factor. However the correction factor is variable in accordance with certain engine pressures and requires the use of elaborate altitude test cell facilities to define it for a practical working range. This invention measures engine pressures in a static sea level facility, derives a correction factor to be applied to one of the measured pressures for use in a determination of gross thrust useful under all operating conditions.
Inventors
- 👤 Donald G Mc
- 👤 G Mackintosh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:45
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/13; G01L5/133
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
160 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine; measuring the values AN, PSO, FG, PSN and PTN, where AN is nozzle entry area, a constant, PSO is ambient static pressure, FG is gross thrust, PSN is nozzle entry static pressure and PTN is nozzle total pressure; using the measured values of AN, PSO, FG and one of PSN and PTN in the following equation: FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) to determine a value for one of P''SN and P''TN respectively, where P''SN is a corrected nozzle entry static pressure, P''TN is a corrected nozzle total pressure and where fF(PTN/PSO) is a function of the nozzle pressure ratio PTN/PSO and h(PTN/PSN) is a function of the pressure ratio PTN/PSN; obtaining the respective functional relationships g1(PSN, PTN) for correcting PSN and g2(PSN,PTN) for correcting PTN according to one of the equations P''SN g1 (PSN, PTN) and P''TN g2(PSN, PTN).
Claim 2
Independent Claim
160 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine; measuring the values AN, PSO, FG, PSN and PTN, where AN is nozzle entry area, a constant, PSO is ambient static pressure, FG is gross thrust, PSN is nozzle entry static pressure and PTN is nozzle total pressure; using the measured values of AN, PSO, FG and one of PSN and PTN in the following equation: FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) to determine a value for one of P''SN and P''TN respectively, where P''SN is a corrected nozzle entry static pressure, P''TN is a corrected nozzle total pressure and where fF(PTN/PSO) is a function of the nozzle pressure ratio PTN/PSO and h(PTN/PSN) is a function of the pressure ratio PTN/PSN; obtaining the respective functional relationships g1(PSN, PTN) for correcting PSN and g2(PSN,PTN) for correcting PTN according to one of the equations P''SN g1 (PSN, PTN) and P''TN g2(PSN, PTN).
Claim 3
Independent Claim
209 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter comprising running a jet engine, determining the condition of operation of the engine as being in one of two conditions where (1) the expansion of the exhaust gas is complete, and (2) where the expansion of the exhaust gas is incomplete measuring the values AN, PSO, FG, PSN and PTN, where AN is nozzle entry area, a constant PSO is ambient static pressure FG is gross thrust PSN is nozzle entry static pressure PTN is nozzle total pressure using these measured values in the following equation FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) with the exception of one of PSN and PTN to determine a value for one of P''SN and P''TN respectively where f(PTN/PSO) fc(PTN/PSO) is a function of the nozzle pressure ratio and h (PTN/PSN) is a function of PTN/PSN for complete expansion when condition (1) exists and where f(PTN/PSO) fI(PTN/PSO) is a function of the nozzle pressure ratio and h(PTN/PSN) is a function of PTN/PSN for incOmplete expansion when condition (2) exists to obtain the respective functional relationship g1(PSN, PTN) for correcting PSN and g2(PSN, PTN) for correcting PTN according to one of the equations P''SN g1(PSN, PTN) and P''TN g2(PSN, PTN).
Claim 4
Independent Claim
209 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter comprising running a jet engine, determining the condition of operation of the engine as being in one of two conditions where (1) the expansion of the exhaust gas is complete, and (2) where the expansion of the exhaust gas is incomplete measuring the values AN, PSO, FG, PSN and PTN, where AN is nozzle entry area, a constant PSO is ambient static pressure FG is gross thrust PSN is nozzle entry static pressure PTN is nozzle total pressure using these measured values in the following equation FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) with the exception of one of PSN and PTN to determine a value for one of P''SN and P''TN respectively where f(PTN/PSO) fc(PTN/PSO) is a function of the nozzle pressure ratio and h (PTN/PSN) is a function of PTN/PSN for complete expansion when condition (1) exists and where f(PTN/PSO) fI(PTN/PSO) is a function of the nozzle pressure ratio and h(PTN/PSN) is a function of PTN/PSN for incOmplete expansion when condition (2) exists to obtain the respective functional relationship g1(PSN, PTN) for correcting PSN and g2(PSN, PTN) for correcting PTN according to one of the equations P''SN g1(PSN, PTN) and P''TN g2(PSN, PTN).
Claim 5
Dependent Claim
24 words
A method as defined in claim 2 in which the step of running said jet engine is on a sea level static test bed.
Claim 6
Dependent Claim
25 words
A method as defined in claim 2 in which the step of running said engine is carried out with the engine in a non-afterburning mode.
Claim 7
Independent Claim
205 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine; measuring the values AN, PSO, FG, PSN, and at least one of PS6 and PT5 and calculating PTN using PSN and said at least one of the independent measured pressures PS6 and PT5 where AN is nozzle entry area, a constant, PSO is ambient static pressure, FG is gross thrust, PSN is nozzle entry static pressure, PTN is nozzle total pressure, PS6 is the static pressure at the flameholder region, and PT5 is the total pressure in the diffuser; using the measured and calculated values in the following equation FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) with the exception of one of the values PSN and PTN to determine a value for one of P''SN and P''TN respectively, where P''SN is a corrected nozzle entry static pressure P''TN is a corrected nozzle total pressure and where f(PTN/PSO) is a function of the nozzle pressure ratio PTN/PSO h(PTN/PSN) is a function of the pressure ratio PTN,/PSN to obtain the respective functional relationship g1(PSN, PTN) for correcting PSN or g2 (PSN, PTN) for correcting PTN according to one of the equations P''SN g1(PSN, PTN) and P''TN g2(PSN, PTN).
Claim 8
Independent Claim
205 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine; measuring the values AN, PSO, FG, PSN, and at least one of PS6 and PT5 and calculating PTN using PSN and said at least one of the independent measured pressures PS6 and PT5 where AN is nozzle entry area, a constant, PSO is ambient static pressure, FG is gross thrust, PSN is nozzle entry static pressure, PTN is nozzle total pressure, PS6 is the static pressure at the flameholder region, and PT5 is the total pressure in the diffuser; using the measured and calculated values in the following equation FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) with the exception of one of the values PSN and PTN to determine a value for one of P''SN and P''TN respectively, where P''SN is a corrected nozzle entry static pressure P''TN is a corrected nozzle total pressure and where f(PTN/PSO) is a function of the nozzle pressure ratio PTN/PSO h(PTN/PSN) is a function of the pressure ratio PTN,/PSN to obtain the respective functional relationship g1(PSN, PTN) for correcting PSN or g2 (PSN, PTN) for correcting PTN according to one of the equations P''SN g1(PSN, PTN) and P''TN g2(PSN, PTN).
Claim 9
Dependent Claim
19 words
A method as defined in claim 5 in which the calculation of PTN is according to the following relationship
Claim 10
Dependent Claim
118 words
A method as defined in claim 5 in which said engine is in the non-afterburning mode and in which the calculation of PTN is according to the following relationship PTN PT5 (1 - a2 PSN/PT5 - b2) where PTN is the total pressure at the nozzle entrance, PT5 is the total pressure in the diffuser, PSn is the static pressure at the nozzle entrance, a2 is a constant representing the slope of the straight line relationship P''''T5-P''''TN/P''''T5 against P''''SN/P''''T5 determined by test with said engine operating without an afterburner in operation, and b2 is a constant representing the intercept of said straight line relationship determined by test without an afterburner in operation on the axis represented by P''''T5-P''''TN/P''''T5.
Claim 11
Dependent Claim
115 words
A method as defined in claim 5 in which said engine is operating in an afterburning mode and PTN is calculated according to the following relationship PTN PT5 (1 - a1 PSN/PT5 - b1) where PTN is the total pressure at the nozzle entrance, PT5 is the total pressure in the diffuser, PSN is the static pressure at the nozzle entrance, a1 is a constant representing the slope of the straight line relationship P''''T5-P''''TN/P''''T5 against P''''SN/P''''T5 determined by test with said engine operating with said afterburner in operation, and b1 is a constant representing the intercept of said straight line relationship, determined by test with said afterburner in operation, on the axis represented by P''''T5-P''''TN/P''''T5.
Claim 12
Independent Claim
100 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine measuring the values AN, PSO, FG, PSN, PS6 and PT5 where AN is nozzle entry area, a constant PSO is ambient static pressure FG is gross thrust PSN is nozzle entry static pressure PS6 is the static pressure at the flameholder region PT5 is the total pressure in the diffuser using the measured values in the following interconnected equations with the exception of PSN to determine P''SN, where P''SN is a corrected nozzle entry static pressure
Claim 13
Independent Claim
100 words
A method for determining a functional relationship for correcting a variable used as an input for a gross thrustmeter, comprising running a jet engine measuring the values AN, PSO, FG, PSN, PS6 and PT5 where AN is nozzle entry area, a constant PSO is ambient static pressure FG is gross thrust PSN is nozzle entry static pressure PS6 is the static pressure at the flameholder region PT5 is the total pressure in the diffuser using the measured values in the following interconnected equations with the exception of PSN to determine P''SN, where P''SN is a corrected nozzle entry static pressure
Claim 14
Dependent Claim
119 words
Apparatus for use in combination with a jet type engine of a type including a diffuser and a nozzle, for determining a corrected static or total pressure at the entrance to the nozzle, comprising pressure responsive means for measuring engine pressures including nozzle entrance static pressure PSN and nozzle entrance total pressure PTN and providing first and second signals representing PSN and PTN respectively. computer means for combining at least said first and second signals to Develop a corrected pressure for one of the group of pressures comprising PSN and PTN and for providing a third signal representing said corrected pressure; and circuit means for connecting said pressure responsive means to said computer means for delivering said signals thereto.
Claim 15
Dependent Claim
119 words
Apparatus for use in combination with a jet type engine of a type including a diffuser and a nozzle, for determining a corrected static or total pressure at the entrance to the nozzle, comprising pressure responsive means for measuring engine pressures including nozzle entrance static pressure PSN and nozzle entrance total pressure PTN and providing first and second signals representing PSN and PTN respectively. computer means for combining at least said first and second signals to Develop a corrected pressure for one of the group of pressures comprising PSN and PTN and for providing a third signal representing said corrected pressure; and circuit means for connecting said pressure responsive means to said computer means for delivering said signals thereto.
Claim 16
Dependent Claim
112 words
Apparatus as defined in claim 10 and further including means to provide a fourth signal representing measured gross thrust FG, means to provide a fifth signal representing nozzle entry area AN, means to provide a sixth signal representing ambient static pressure PSO, and in which said computer means combines one of said first and second signals, and said fourth, fifth and sixth signals in the following manner FG AN.PSO.PTN/PSO.f(PTN/PSO).h(PTN/PSN) where f(PTN/PSO) is a function of the nozzle pressure ratio PTN/PSO h(PTN/PSN) is a function of the pressure ratio PTN/PSN, to determine a corrected value for the other of said first and second signals, said corrected value being represented by said third signal.
Claim 17
Dependent Claim
87 words
Apparatus for use in a jet type engine including a diffuser and a nozzle, for determining a corrected nozzle entrance static pressure PSN, comprising pressure responsive means for measuring engine pressures including PSN, static pressure in the flameholder region PS6 and total pressure in the diffuser PT5, and providing a first, second and third signal representing PSN, PS6 and PT5 respectively, and computer means for combining at least said first, second and third signals to develop a corrected pressure P''SN and providing a fourth signal representing P''SN.
Claim 18
Dependent Claim
87 words
Apparatus for use in a jet type engine including a diffuser and a nozzle, for determining a corrected nozzle entrance static pressure PSN, comprising pressure responsive means for measuring engine pressures including PSN, static pressure in the flameholder region PS6 and total pressure in the diffuser PT5, and providing a first, second and third signal representing PSN, PS6 and PT5 respectively, and computer means for combining at least said first, second and third signals to develop a corrected pressure P''SN and providing a fourth signal representing P''SN.
References Cited (Backward Citations)
US3233451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |