Method for checking the maximum available power of a turbine engine of an aircraft equipped with two turbine engines

Abstract

A method for checking the maximum available power of a turbine engine of an aircraft equipped with two turbine engines configured to operate in parallel and together to supply a necessary power to the aircraft during a flight phase includes: placing one of the turbine engines in a maximum take-off power regime, and adjusting a power supplied by the other turbine engine, such that the turbine engines continue to supply the necessary power to the aircraft during the flight phase; determining a power supplied by the turbine engine placed in the maximum take-off power regime, and processing the supplied power determined in this way, in order to deduce a piece of information relating to the maximum available power.

Claims

1. A method of checking a maximum available power of a turbine engine of an aircraft equipped with two turbine engines configured to operate in parallel and together to supply the aircraft with a necessary power during a flight phase, said method comprising: placing a first of the two turbine engines in an engine speed equal to an engine speed at maximum take-off power, adjusting a power supplied by a second of the two turbine engines, so that the two turbine engines keep supplying the aircraft with the necessary power during the flight phase, determining a power supplied by the first turbine engine while the first turbine engine is being placed in the engine speed at maximum take-off power, and processing the thus determined supplied power in order to deduce an information pertaining to the maximum available power.

2. The method according to claim 1, further comprising: determining a threshold power, said threshold power corresponding to a minimum power to be reached by the turbine engine placed in the engine speed at maximum take-off power in an event of failure of the other turbine engine, comparing the thus determined supplied power with the threshold power.

3. The method according to claim 1, wherein the turbine engine placed in the engine speed at maximum take-off power comprises a high pressure turbine and a low pressure turbine, the method further comprising: measuring a temperature of the gases between the high pressure turbine and the low pressure turbine of the turbine engine placed in the engine speed at maximum take-off power, and comparing the measured temperature with a predetermined threshold temperature, so as to ensure that the measured temperature is lower than the threshold temperature.

4. The method according to claim 1, further comprising: measuring a rotation speed of the turbine engine placed in the engine speed at maximum take-off power, and comparing the measured rotation speed with a predetermined threshold rotation speed so as to ensure that the measured rotation speed is higher than or equal to the threshold rotation speed.

5. The method according to claim 1, further comprising: determining an operating power, said operating power corresponding to a minimum power guaranteeing a re-acceleration of the second of the two turbine engines in an event of failure of the turbine engine placed in the engine speed at maximum take-off power, and adjusting the power of the turbine engine placed in the engine speed at maximum take-off power such that the power supplied by the second of the two turbine engines remains higher than the determined operating power.

6. The method according to claim 1, wherein the turbine engine placed in the engine speed at maximum take-off power comprises a high pressure shaft and a low pressure shaft, and wherein the method is automatically interrupted when at least one of the following conditions is fulfilled: rotation speed of the high pressure shaft is lower than a first threshold rotation speed, rotation speed of the low pressure shaft is lower than a second threshold rotation speed and higher than a third threshold rotation speed, a failure is detected on one of the two turbine engines.

7. A non-transitory computer readable medium comprising code instructions for executing the method according to claim 1 when the code instructions are executed by a processor.

8. A controlling device comprising a computer configured to implement the method according to claim 1, said computer being configured to implement the following steps: placing the first turbine engine in the engine speed equal to the engine speed at maximum take-off power, adjusting the power supplied by the second turbine engine, such that the two turbine engines continue supplying the aircraft with the necessary power during the flight phase, determining the power supplied by the first turbine engine while the first turbine engine is being placed in the engine speed at maximum take-off power, and processing the thus determined power supplied to deduce the information pertaining to the maximum available power.

9. An assembly comprising two turbine engines configured to operate in parallel and together to supply a necessary power for an aircraft during a flight phase, said assembly comprising the controlling device according to claim 8.

10. An aircraft comprising two turbine engines configured to operate in parallel and together to supply a necessary power for the aircraft during a flight phase, said aircraft comprising a computer configured to implement the method according to claim 1.

11. A method of checking a maximum available power of a turbine engine of an aircraft equipped with two turbine engines configured to operate in parallel and together to supply the aircraft with a necessary power during a flight phase, said method comprising: placing a first of the two turbine engines in an engine speed equal to an engine speed at maximum take-off power, adjusting a power supplied by a second of the two turbine engines, so that the two turbine engines keep supplying the aircraft with the necessary power during the flight phase, determining a power supplied by the turbine engine placed in the engine speed at maximum take-off power, determining a threshold power, said threshold power corresponding to a minimum power to be reached by the turbine engine placed in the engine speed at maximum take-off power in an event of failure of the other turbine engine, and comparing the thus determined supplied power with the threshold power.

12. A method of checking a maximum available power of a turbine engine of an aircraft equipped with two turbine engines configured to operate in parallel and together to supply the aircraft with a necessary power during a flight phase, said method comprising: placing a first of the two turbine engines in an engine speed equal to an engine speed at maximum take-off power, determining an operating power, said operating power corresponding to a minimum power guaranteeing a re-acceleration of a second of the two turbine engines in an event of failure of the turbine engine placed in the engine speed at maximum take-off power, adjusting a power of the turbine engine placed in the engine speed at maximum take-off power such that a power supplied by the second of the two turbine engines remains higher than the determined operating power, determining a power supplied by the turbine engine placed in the engine speed at maximum take-off power, and processing the thus determined supplied power in order to deduce an information pertaining to the maximum available power.

Description

PRESENTATION OF THE FIGURES

(1) Other characteristics, purposes and advantages of the invention will become apparent from the following description, which is purely for illustrative purposes and is non-limiting, and which should be read in light of the accompanying drawings, whereon:

(2) FIG. 1 (already described) is a diagram illustrating the total power variation required according to time to successfully carry out a shipwreck rescue mission by means of a helicopter comprising two turbine engines;

(3) FIG. 2 is a schematic representation of a helicopter according to an embodiment of the invention;

(4) FIG. 3 is a schematic representation of a helicopter controlling device illustrated on FIG. 2;

(5) FIG. 4 illustrates a method for checking the maximum available power of a turbine engine of an aircraft according to an embodiment of the invention.

DETAILED DESCRIPTION

(6) FIG. 2 shows an aircraft 10, in particular a helicopter, comprising means for implementing a method 100 of checking the maximum available power of an aircraft 10 turbine engine according to an embodiment of the invention.

(7) The helicopter 10 is equipped with a first turbine engine 11 and a second turbine engine 12 configured to operate in parallel and supply together a power P.sub.1+2 required for the flight phase of the helicopter 10. More particularly, the first and second turbine engines respectively output a power P.sub.1 and P.sub.2 to a main transmission gearbox BTP so that the latter transmits the power P.sub.1+2 to a main rotor (not represented) of the helicopter 10.

(8) Each of the turbine engines 11, 12 comprises from upstream to downstream, in the flow direction of the gases, a fan, a low pressure compressor, a high pressure compressor, a combustion chamber, a high pressure turbine, a low pressure turbine and a gas exhaust nozzle.

(9) The helicopter 10 is further equipped with a controlling device 13 of which FIG. 3 is a schematic representation.

(10) The controlling device 13 comprises a computer 14 configured to send control instructions to the first turbine engine 11 and to the second turbine engine 12 by means of an output interface 15. More precisely, the computer 14 is configured to implement the following steps consisting in: placing one of the turbine engines 11, 12 in a engine speed that is substantially equal to a PMD power engine speed (step 101), and adjusting the power supplied P.sub.2, P.sub.1 by the other of the turbine engines 12, 11 (step 102), such that the turbine engines 11, 12 output the power P.sub.1+2 required for the helicopter 10 during the flight phase thereof, determining the power supplied P.sub.1, P.sub.2 by the turbine engine 11, 12 placed in engine speed at maximum take-off power (PMD) (step 103), and processing the thus determined power supplied P.sub.1, P.sub.2 to deduce an information pertaining to the maximum available power (steps 105, 106).

(11) The power P.sub.1+2 is for example sent to the controlling device 13, in particular to the computer 14, by means of a user interface 16 connected to the controlling device 13 by an input interface 17. The user interface 16 can be further configured to display status information about the aircraft 10 for a pilot or operator. For this, the user interface 16 is also connected to the controlling device 13 by the output interface 15.

(12) In order to guarantee a rapid re-acceleration in the event of failure of the turbine engine being tested (that is to say, the machine that is brought to the PMD engine speed), the power of the other turbine engine is adjusted according to the effective requirement of the helicopter 10 while remaining higher than a minimum power value guaranteeing such a re-acceleration. The compliance with this minimum power by the other turbine engine can then prevent the turbine engine being tested to reach PMD: however, the power attained by the turbine engine being tested remains sufficiently close to the PMD so that controlling can be carried out effectively.

(13) The controlling device 13 can further comprise: a data memory 18 wherein for example are preregistered a predetermined threshold power P.sub.s, a predetermined threshold temperature T.sub.s and a predetermined threshold rotation speed NG.sub.s, which are used by the computer 14 as shall be explained in the rest of the description. a program memory 19 wherein is for example preregistered the method 100, and at least one communication bus 20.

(14) As indicated above, the threshold power (Ps) is a minimum power to be reached by the turbine engine 11, 12 placed in PMD engine speed in the event of failure of the other turbine engine. It can for example be equal to the minimum power value declared by the manufacturer in the performance tables to help the crew determine the permissible useful loads.

(15) The threshold temperature (T.sub.s) is for example equal to the minimum temperature value between the high pressure turbine of the gas generator and the low pressure turbine declared by the manufacturer in the performance tables which are intended for the crew to determine the permissible useful loads.

(16) The threshold rotation speed (NG.sub.s) is for example equal to the minimum value of the nominal rotation speed NG of the turning parts of the gas generator declared by the manufacturer in the performance tables intended for the crew to determine the permissible useful loads.

(17) In one embodiment, to process the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in the PMD power engine speed, the computer 14 is also configured to compare the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in the PMD power engine speed at threshold power P.sub.s, so as to ensure that the power supplied P.sub.1, P.sub.2 is higher than or equal to the threshold power Ps.

(18) More particularly, if the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in the PMD power engine speed is higher than or equal to the threshold power P.sub.s, the computer 14 is for example configured to command the user interface 16 to inform the pilot or operator that the turbine engine 11, 12 placed in PMD power engine speed can supply the threshold power P.sub.s. The threshold power P.sub.s hence corresponds to a guaranteed minimum power in the event of failure of the turbine engine 12, 11 whereof the power P.sub.2, P.sub.1 supplied is adjusted. On the contrary, that is to say, if the supplied power P.sub.1, P.sub.2 is lower than the threshold power P.sub.s, the computer 14 can also be configured to command the user interface 16 to inform the pilot or operator that the turbine engine 11, 12 placed in the PMD power engine speed cannot supply the guaranteed minimum power and that there is a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted.

(19) So that the computer 14 can determine the power supplied P.sub.1, P.sub.2 by the turbine engines 11,12, each turbine engine 11, 12 comprises for example a measuring device 21, 22 connected to the controlling device 13 by the input interface 17 and comprising: a first sensor 23, 24 configured to measure a torque C.sub.1, C.sub.2 provided by the turbine engine 11, 12, and a second sensor 25, 26 configured to measure a rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12.

(20) Measurement of the torques C.sub.1 and C.sub.2 can for example be carried out at the output of each turbine engine 11, 12, that is to say, at their intermediate input shaft of the transmission gearbox.

(21) The computer 14 is thus configured to compute the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in PMD power engine speed based on torque measurements C.sub.1, C.sub.2 and the rotation speed NG.sub.1, NG.sub.2 carried out by the first and second sensors 23 to 26.

(22) In one embodiment, the computer 14 can also be configured to compare a temperature T.sub.1, T.sub.2 measured between the high pressure turbine and the low pressure turbine of the turbine engine 11, 12 placed in PMD power engine speed at the threshold temperature T.sub.s, so as to ensure that the measured temperature T.sub.1, T.sub.2 is lower than the threshold temperature T.sub.s (steps 108 to 110).

(23) More particularly, if the temperature T.sub.1, T.sub.2 thus measured in the turbine engine 11, 12 placed in the PMD power engine speed is lower than the threshold temperature T.sub.s, the computer 14 is for example configured to command the user interface 16 to inform the pilot or operator that the temperature T.sub.1, T.sub.2 does not exceed the threshold temperature T.sub.s, that is to say, that the turbine engine 11, 12 placed in the PMD power engine speed does not overheat, when the engine is at maximum rotation speed corresponding to the PMD power engine speed (step 109).

(24) In the opposite case, that is to say, if the measured temperature T.sub.1, T.sub.2 of the turbine engine 11, 12 placed in PMD power engine speed is higher than or equal to the threshold temperature T.sub.s, the computer 14 can also be configured to command the user interface 16 to inform the pilot or the operator that the turbine engine 11, 12 placed in the PMD power engine speed overheats with this engine speed and that there exists a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted (step 110).

(25) In order to measure the temperature T.sub.1, T.sub.2 of the turbine engines 11, 12, the measuring device 21, 22 of each turbine engine 11, 12 comprises for example a third sensor 27, 28 configured to measure the temperature T.sub.1, T.sub.2 between the high pressure turbine and the low pressure turbine of the turbine engine 11, 12.

(26) In one embodiment, the computer 14 can also be configured to compare a measured rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in the PMD power engine speed at the threshold rotation speed NG.sub.s, such as to ensure that the measured rotation speed NG.sub.1, NG.sub.2 is higher than or equal to the threshold rotation speed NG.sub.s (steps 111-114).

(27) More particularly, if the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in the PMD power engine speed is higher than or equal to the threshold rotation speed NG.sub.s, the computer 14 is for example configured to command the user interface 16 to inform the pilot or operator that the turbine engine 11, 12 placed in the PMD power engine speed can reach the threshold rotation speed NG.sub.S, when the latter is at the maximum temperature corresponding to the PMD power engine speed (step 113).

(28) In the opposite case, that is to say, if the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in the PMD power engine speed is lower than the threshold rotation speed NG.sub.S, the computer 14 can also be configured to command the user interface 16 to inform the pilot or operator that the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in PMD power engine speed is limited by the maximum temperature corresponding to the PMD power engine speed and that there is a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted (step 114).

(29) In order to measure the rotation speed NG.sub.1, NG.sub.2 of the turbine engines 11, 12, the measuring device 21, 22 of each turbine engine 11, 12 comprises for example the second aforementioned sensor 25, 26.

(30) In one embodiment, the checking method 100 is automatically interrupted when one at least of the three following conditions is fulfilled: the rotation speed N1 of the high pressure shaft is lower than a threshold rotation speed N1.sub.S the rotation speed N2 of the low pressure shaft is lower than a threshold rotation speed N1.sub.S1 and higher than a threshold rotation speed N1.sub.S1 and/or a failure is detected on one of the turbine engines 11, 12 (OEI engine speed).

(31) The FIG. 4 shows a method 100 of checking the maximum available power of one of the turbine engines 11, 12 of the helicopter 10.

(32) The method 100 is for example initiated by the pilot or the operator by means of the user interface 16.

(33) Preferably, the method 100 is carried out during each flight for each turbine engine 11, 12. In other words, at each flight, it is preferable to check the maximum power that each of the turbine engines 11, 12 is able to supply.

(34) Furthermore, the method 100 is preferably carried out during a flight phase throughout which the result of a failure of any one of the turbine engines 11, 12 would be minimal, for example during a coasting phase, near a diversion surface.

(35) The method 100 comprises the following steps: placing one of the turbine engines 11, 12 in the PMD power engine speed (101), and adjusting the supplied power P.sub.2, P.sub.1 by the other turbine engine 12, 11 (102), such that the turbine engines 11, 12 output the power P.sub.1+2 required for the helicopter 10 during its flight phase. determining a power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in the engine speed at maximum take-off power (PMD) (103), and processing the thus, determined supplied power P.sub.1, P.sub.2 to deduce an information pertaining to the maximum available power (104).

(36) Preferably, the processing step 104 is carried out by comparing the thus, determined supplied power P.sub.1, P.sub.2 with the threshold power P.sub.S, such as to ensure that the supplied power P.sub.1, P.sub.2 is higher than or equal to the threshold power P.sub.S.

(37) If need be, the power of the other turbine engine 12, 11 is adjusted according to the effective requirement of the helicopter while remaining higher than a minimum power value guaranteeing such a re-acceleration.

(38) Then, if the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in the PMD power engine speed is higher than or equal to the threshold power P.sub.S, the method 100 comprises for example a step 105 during which the pilot or the operator is informed that the turbine engine 11, 12 placed in PMD power engine speed can supply the guaranteed minimum power.

(39) On the contrary, that is to say, if the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in PMD power engine speed is lower than the threshold power P.sub.S, the method 100 comprises for example a step 106 during which the pilot or the operator is informed that the turbine engine 11, 12 placed in PMD power engine speed cannot supply the guaranteed minimum power and that there is a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted.

(40) The power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in PMD power engine speed is for example determined during the steps consisting in: measuring the torque C.sub.1, C.sub.2 supplied by the turbine engine 11,12; measuring the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 and computing the power P.sub.1, P.sub.2 supplied by the turbine engine 11, 12 placed in PMD power engine speed based on the measurements of torque C.sub.1, C.sub.2 and rotation speed NG.sub.1, NG.sub.2 performed beforehand.

(41) The method 100 can also comprise the following steps: measuring the temperature T.sub.1, T.sub.2 between the high pressure turbine and the low pressure turbine of the turbine engine 11, 12 placed in PMD power engine speed (107), and comparing the thus, measured temperature T.sub.1, T.sub.2 with the threshold temperature T.sub.S, in such a way as to ensure that the measured temperature T.sub.1, T.sub.2 is lower than the threshold temperature T.sub.S (108).

(42) Then if the temperature T.sub.1, T.sub.2 by the turbine engine 11, placed in PMD power engine speed is lower than the threshold temperature T.sub.S, the method 100 comprises for example a step 109 during which the pilot or the operator is informed that the turbine engine 11, 12 has not overheated on the PMD power engine speed, when the engine is at maximum rotation speed corresponding to the PMD power engine speed.

(43) In the opposite case, that is to say, if the temperature T.sub.1, T.sub.2 by the turbine engine 11, 12 placed in the PMD power engine speed is lower than the threshold temperature T.sub.S, the method 100 for example comprises a step 110 during which the pilot or the operator is informed that the turbine engine 11, 12 placed in the PMD power engine speed overheats on this engine speed and that there is a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted.

(44) The method 100 can also comprise the following steps: measuring 111 the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in PMD power engine speed, and comparing 112 the thus measured rotation speed NG.sub.1, NG.sub.2 with the threshold rotation speed NG.sub.S, such as to ensure that the measured rotation speed NG.sub.1, NG.sub.2 is higher than or equal to the threshold rotation speed NG.sub.S.

(45) Then, if the rotation speed NG.sub.1, NG.sub.2 of the turbine engine 11, 12 placed in the PMD power engine speed is higher than or equal to the threshold rotation speed NG.sub.S, the method 100 comprises for example a step 113 during which the pilot or the operator is informed that the turbine engine 11, 12 placed in the PMD power engine speed can reach the threshold rotation speed NG.sub.S, when the latter is at maximum temperature corresponding to the PMD power engine speed.

(46) On the contrary, that is to say, if the rotation speed NG.sub.1, NG.sub.2 is lower than the threshold rotation speed NG.sub.S, the method 100 comprises for example a step 114 during which the pilot or operator is informed that the rotation speed NG′, NG.sub.2 of the turbine engine 11, 12 placed in PMD power engine speed is limited by the maximum temperature corresponding to the PMD power engine speed and that there is a danger in the event of failure of the turbine engine 12, 11 whereof the supplied power P.sub.2, P.sub.1 has been adjusted.

(47) The aforementioned helicopter 10 and method 100 allow us to ensure that each turbine engine 11, 12 is able to output maximum power in each engine speed, in particular in engine speeds corresponding to particularly high power such as on take-off (PMD power) or OEI engine speed.

(48) Particularly, the fact of using the PMD power engine speed to check the maximum available power of each turbine engine 11, 12 is particularly advantageous as far as that in this engine speed, the level of power supplied by the turbine engine 11, 12 does not risk damaging it.

(49) The fact of using the PMD power engine speed to check the maximum available power of each turbine engine 11, 12 also has the following advantages: anticipating undetected or underlying failures of the turbine engines 11, 12 or of the engine fuel circuit (clogging, erosion, corrosion, creep, strikes, vibrations, cracking, plugging, leaks, etc.), reducing the duration of exposure to undetected failure, in particular when the method 100 is carried out at each flight for each turbine engine 11, 12, causing a possible fault of the turbine engine 11, 12 placed in PMD power engine speed in flight conditions, particularly in coasting phase, in conditions where consequences of such a fault are minimised. In fact, in the event of a fault of any of the turbine engines 11, 12 the other turbine engine 12, 11 shall be less used in coasting phase than in any other flight phase, thereby, limiting the risks of cascade effects, that is to say, the loss of any of the turbine engines 11, 12, then of the other turbine engines 12, 11, avoiding maintenance operations and hence human interventions on the turbine engines 11, 12 which can, themselves generate new risks, being able to be completed by a known EPC, allowing the checking method 100 to be applied on any type of flight, and particularly a commercial flight, the helicopter 10 not being in a single-engine flight, guaranteeing a sufficiently short restarting time for the turbine engine that has not been tested whatever the flight conditions, so as to ensure an easy landing of the helicopter in OEI engine speed.

(50) The turbine engine 11, 12 data collected during the method 100 can further be stored in the data memory 18 with a view to be analysed on the ground such as to determine if the turbine engine 11, 12 can keep being used or not. The results of these analyses allow for example to better ensure the maximum available power of the turbine engine 11, 12 in each engine speed for the following flights.

(51) Finally, the method 100 also has the advantage of being able to be carried out on any type of flight (commercial or technical) and to not hinder the latter whether it be in terms of speed, altitude, etc.