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Tests on the motor stands SAU

Tests on the motor stands SAU

Bench tests of the ACS on the motor are carried out both for research purposes and in the process of developing, debugging, and presentation of the engine to the customer.

Research tests are carried out for the experimental test in actual use of new methods of management and hardware solutions and, in contrast to the test systems developed for specific engines, can be conducted on a specially prepared motor-demonstrator, and not on the engine, which is designed for the system.

Experimental studies SAU GTE in a closed circuit do not often carried out on the engines, and semi-natural non-motorized stands with feedback on which real instruments ACS works with a mathematical model of the engine. This is due to the fact that the control system on the engine test are expensive and usually limited to the verification of its performance in normal version, or close to it. In addition, for research testing capabilities are very limited.

However, ACS test engine is allowed to increase reliability of research, since the accuracy of the test results on the HIL stands feedback is low due to the action of a number of removable hard factors. These include, for example, include the effect of bench systems performance (fuel, pneumatic, electrical, load systems). They provide the same interaction as it occurs on the motor, it is difficult for modeling changes in operating conditions and engine operating conditions.

Noticeable static and dynamic errors introduced operated actuators simulating engine transducers electrical signals into physical quantities workflow engine parameters (speed, pressure and temperature of the gas and air), formed in its mathematical model. Precise their compensation is virtually impossible.

It may not be reproduced features of the measurement control parameters, such as those associated with the effect of irregularities, ripples.

engine model used in the semi-natural stand, also not adequately reflect its characteristics.

Carrying out of research works in the field of automatic control on the engine becomes more effective when using a special motor stand that has the capabilities to flexibly change the composition of the equipment connected to the engine of the automatic control system, which has a permanently operating extended sensor set and the possibility of non-standard engine preparation, an information and measurement system that allows carrying out specific Measurements for non-stationary control problems, a special system with a model Engine, allowing to check and debug the equipment before the start of testing on the engine, a complex of engine protection systems, etc.

Preparatory stage

It is important to have on such a stand the possibility of promptly changing the composition of ACS equipment connected to the engine and a set of sensors. At the same time, test test control systems should allow reconfiguration of the ACS composition in the process of testing it without stopping the engine. To ensure safety tests during reconfiguration, the engine can be transferred to work with its standard ACS. A block diagram of the test management system is shown in 5.3.

Block switching engine management system switches the flow of control commands to the actuators of the

standard or experimental ACS. When switching the control system with the engine running is important, if necessary, without appreciable changes to implement the flow transfer fuel supply to the combustion chamber of the pump to the regular high-pressure pump (NVD) Experimental ACS. For safe operation on the stand is useful to be able to start the engine when the staff of ACS, and then move on to work on the pilot control system.

The methodology of experimental research on the engine demonstrator is expedient to provide two phases: a preparatory (Technology) and the main stage of the work with an experienced ACS.

The main task of the preparatory stage is to check before the tests on the engine the performance of all the experimental units. This check is performed by transferring the electronic digital controller of the experimental ACS to the operating mode with the mathematical model of the engine. The simulated operation of the engine can be changed by applying a control signal from the throttle to the input of the pilot ACS regulator. The signal about the actual fuel consumption enters the mathematical model of the engine. At the same time, the high-pressure pump of the high-pressure switch works on the equivalent of injectors. By simulating a change in the engine operating mode, the control of the movement of the guiding devices and the operation of the air bypass valves are checked. Toggle Tp serves to transfer control of the engine from one ACS to another.

The purpose bench tests or finishing ACS at presentation engine to the customer to verify and confirm its performance, functionality and manageability of the engine in the desired range of operating conditions and modes of operation of the engine. Tests are carried out on the ground, altitude and climatic stands.

Tests are automatic control system made according to the basic design and technological documentation. Typically, ACS tests are combined with engine tests to determine its basic characteristics and are not intended to special works on the control system.

The automatic control system is considered efficient when performing functions specified in the ToR with the required performance (accuracy, duration transients range of parameter changes, etc..) at all engine operating conditions in all operating conditions.

Installation of electronic devices

By handling is meant the ability provided by the engine management system to store and change the operating mode, defined by a throttle or when an external signal at predetermined operating conditions of the engine at the desired characteristics in the steady-state and transient operation.

When installing electronic devices is motor assessment of their performance in a high-rise stand is not performed.

When tested on a high-altitude stand, the operability of the automatic control system and the controllability of the engine are determined in the operational range of altitude and flight speed changes in the steady-state operation modes of the engine from the MG mode to the maximum (take-off) or emergency mode, and from the minimum to full-boost mode (for the FCC engine) , In autorotation modes, as well as in transient modes at startup, acceleration, throttling, turning on and off the FCC, triggering the surge protection system, reversing device and Other elements that make up the engine.

The validation of the engine and its automatic control system on the transient only possible on tall stands, with a special control system, allowing to support these modes constant air flow conditions at the inlet of the engine (px, Tin) and at its output.

The program works by checking the performance of ACS and engine controllability at high altitude and climate stands in agreement with the engine test program on the aircraft.

The tests evaluated quality of all ACS functions specified in the ToR:

- the magnitude of the deviations from the specified values ​​of the adjustable parameters in steady-state and transient modes of operation;

- transient time;

- the stability of the values ​​of the adjustable parameters of the engine when the operating conditions change.

Evaluation of regulation errors made in accordance with the regulations, TK and instruction manual.

Engine and ACS before the test should be completed with the necessary systems, provide measurement of monitored parameters. For each engine list of monitored parameters ACS is determined in accordance with the instructions for operation of the engine.

During the tests, the parameters that characterize the work of the ACS, recorded:

- poster control system using the main and additional sensors in accordance with the instruction manual;

- built-in ACS control system;

- BSKD.

Metrological class measuring systems, as well as recording devices should be determined taking into account the accuracy requirements laid down in the specifications and technical documentation of ACS.

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