Patent US3835701A successfully refreshed from Google Patents.
US3835701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining the thrust of a jet engine
Assignee: Canada Data Ca Ltd
•
Filing: 1972-01-31
•
Granted: 1974-09-17
•
Expires: 1992-01-31
Abstract
Abstract Apparatus is known for determining gross thrust in jet engines by measuring various internal pressures, including measurement of total pressure at the nozzle entrance by means of an immersed probe. The immersed probe has a very short life when an afterburner is used in the engine. The apparatus for the invention is able to determine total pressure at the nozzle entrance, without an immersed probe, from the total pressure in the diffuser and the static pressure at the nozzle entrance. Another embodiment makes use of an additional static pressure in the flameholder region. Also, the invention is for determining the gross thrust of an engine and it distinguishes between an engine with a nozzle operating in a choked condition and an unchoked condition.
Inventors
- 👤 J Murphy
- 👤 E Plett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:15
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/13; G01L5/133
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
Apparatus for use in combination with a jet type engine having a diffuser and a nozzle, for determining the total pressure at the entrance to the nozzle, comprising pressure responsive means for detecting the total pressure in the diffuser and providing a first signal representative of said total pressure, pressure responsive means for detecting the static pressure at the nozzle entrance and providing a second signal representative of said static pressure, pressure responsive means, positioned between the upstream side of the diffuser and the nozzle entrance and upstream of said pressure responsive means for detecting the static pressure at said nozzle entrance, for detecting static pressure and providing a fourth signal representative of said static pressure, computer means for combining said first and second signals in a predetermined manner to provide a third signal representing total pressure at the nozzle entrance, said computer means being constructed to combine said fourth signal with said first and second signals in a predetermined manner to provide said third signal according to the relationship
Claim 2
Dependent Claim
170 words
Apparatus for use in combination with a jet type engine having a diffuser and a nozzle, for determining the total pressure at the entrance to the nozzle, comprising pressure responsive means for detecting the total pressure in the diffuser and providing a first signal representative of said total pressure, pressure responsive means for detecting the static pressure at the nozzle entrance and providing a second signal representative of said static pressure, pressure responsive means, positioned between the upstream side of the diffuser and the nozzle entrance and upstream of said pressure responsive means for detecting the static pressure at said nozzle entrance, for detecting static pressure and providing a fourth signal representative of said static pressure, computer means for combining said first and second signals in a predetermined manner to provide a third signal representing total pressure at the nozzle entrance, said computer means being constructed to combine said fourth signal with said first and second signals in a predetermined manner to provide said third signal according to the relationship
Claim 3
Dependent Claim
244 words
A gross thrust meter for use in combination with a jet type engine which includes a diffuser and a nozzle having an entrance and an exhaust, said thrust meter comprising pressure responsive means for detecting total pressure PT5 in the diffuser and providing a first analog signal representing this pressure; pressure responsive means for detecting only one pressure at the nozzle entrance, said one pressure being static pressure PSN at the nozzle entrance, and providing a second analog signal representing this pressure; pressure responsive means for providing a third signal representing a pressure P6 which is the static pressure at a position within said engine in the flameholder region; means for producing an analog signal representing ambient static pressure; means for producing a signal indicative of whether said nozzle is convergent or convergent-divergent; means for producing a signal indicative of the choked or unchoked operating mode of said engine; an analog to digital converter for receiving said first, second and third signals, and said analog signal representing ambient static pressure Pso, and for providing output data including data representing the pressures PT5, PSN and Pso, computer means for receiving said output data and digital data representing predetermined constants and values associated with engine operation, and providing an output representative of gross thrust, said computer means including logic for evaluating input data to provide PTN, the total pressure at the nozzle entrance, including means for combining PSN, PT5 and PS6 according to the following relationship:
Claim 4
Dependent Claim
244 words
A gross thrust meter for use in combination with a jet type engine which includes a diffuser and a nozzle having an entrance and an exhaust, said thrust meter comprising pressure responsive means for detecting total pressure PT5 in the diffuser and providing a first analog signal representing this pressure; pressure responsive means for detecting only one pressure at the nozzle entrance, said one pressure being static pressure PSN at the nozzle entrance, and providing a second analog signal representing this pressure; pressure responsive means for providing a third signal representing a pressure P6 which is the static pressure at a position within said engine in the flameholder region; means for producing an analog signal representing ambient static pressure; means for producing a signal indicative of whether said nozzle is convergent or convergent-divergent; means for producing a signal indicative of the choked or unchoked operating mode of said engine; an analog to digital converter for receiving said first, second and third signals, and said analog signal representing ambient static pressure Pso, and for providing output data including data representing the pressures PT5, PSN and Pso, computer means for receiving said output data and digital data representing predetermined constants and values associated with engine operation, and providing an output representative of gross thrust, said computer means including logic for evaluating input data to provide PTN, the total pressure at the nozzle entrance, including means for combining PSN, PT5 and PS6 according to the following relationship:
Claim 5
Independent Claim
100 words
A method for determining the total pressure at the entrance to the nozzle of a jet engine without using an immersed probe comprising detecting the total pressure PT5 in the diffuser of said engine; detecting the static pressure PSN at the nozzle entrance; detecting the static pressure PS6 at a position within the engine between the upstream side of the diffuser and the nozzle entrance; producing signals representing the detected pressures and combining at least these signals in a predetermined manner to obtain a signal proportional to the total pressure PTN at the nozzle entrance, in accordance with the relationship
Claim 6
Independent Claim
100 words
A method for determining the total pressure at the entrance to the nozzle of a jet engine without using an immersed probe comprising detecting the total pressure PT5 in the diffuser of said engine; detecting the static pressure PSN at the nozzle entrance; detecting the static pressure PS6 at a position within the engine between the upstream side of the diffuser and the nozzle entrance; producing signals representing the detected pressures and combining at least these signals in a predetermined manner to obtain a signal proportional to the total pressure PTN at the nozzle entrance, in accordance with the relationship
Claim 7
Dependent Claim
119 words
Apparatus for use in combination with a jet engine for determining the total pressure at the entrance to the nozzle of the engine without using an immersed probe comprising means for detecting the total pressure PT5 in the diffuser of said engine; means for detecting the static pressure PSN at the nozzle entrance; means for detecting the satic pressure PS6 at a position within the engine between the upstream side of the diffuser and the nozzle entrance; means for producing signals representing the detected pressures and combining at least these signals in a predetermined manner to obtain a signal proportional to the total pressure PTN at the nozzle entrance, in accordance with the relationship PTN f(PSN, PS6, and PT5).
Claim 8
Dependent Claim
119 words
Apparatus for use in combination with a jet engine for determining the total pressure at the entrance to the nozzle of the engine without using an immersed probe comprising means for detecting the total pressure PT5 in the diffuser of said engine; means for detecting the static pressure PSN at the nozzle entrance; means for detecting the satic pressure PS6 at a position within the engine between the upstream side of the diffuser and the nozzle entrance; means for producing signals representing the detected pressures and combining at least these signals in a predetermined manner to obtain a signal proportional to the total pressure PTN at the nozzle entrance, in accordance with the relationship PTN f(PSN, PS6, and PT5).
References Cited (Backward Citations)
US3258958A
Cited
US3233451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |