J-XY - maybe J-35 - next generation carrier-borne fighter


by78

Brigadier
(Continued from above...)

Electronic controller lightning protection

The electronic controller box is an all-metal shielded structure, which theoretically forms a complete electrical shield and has a good overlap with the aircraft structure. The overlap resistance is not more than 5mΩ, which can quickly lead out the lightning current; shield the signal cable , And the shielding layer has a good overlap with the aircraft structure; except for the overlap terminal, the live parts at any position are kept insulated from the basic structure of the aircraft; by increasing the threshold of circuit damage and malfunction to reduce their vulnerability . So that the transient current entering the electronic controller will not damage the circuit or cause the circuit function to fail; the input/output signal is designed for lightning protection, and the transient suppression is added between the input/output signal of the electronic controller and the shell ground The circuit design to improve the anti-damage level, select the device with a certain degree of protection, increase the overvoltage and overcurrent protection; the hardware design to improve the ability of the functional circuit to withstand abnormalities, adopt a certain functional redundancy design and Fault isolation technology to prevent the propagation of faults and avoid adverse effects on other functional circuits.

Other designs

The weak, small signal and strong and large signal lines between the aviation socket and the motherboard are routed separately; the components on the module are arranged as compact as possible to reduce the length of the wiring, especially the high-frequency bus; the high-reliability needle-shaped printed circuit is adopted Board socket; when designing a printed circuit board (PCB), set the mirror ground and power supply to reduce ground circulation; try to route high-speed clock signals on the same printed board layer; minimize the vias of the printed board; adjacent Try to avoid parallel routing of the two signal layers; perform necessary processing for the digital input and output circuits, and arrange the ground wires of the digital input and output circuits separately; the power supply of each circuit inside the electronic controller adopts an isolated DC/DC converter, In the PCB design work, the internal circuit routing uses each functional circuit partition for routing.

Optimized design of ignition system

Compared with other engines, the ignition device of the carrier-based engine has a higher output voltage and higher frequency. The power input is in accordance with the requirements of GJB181B. The high-voltage output port and the power input port overlap will cause electromagnetic coupling, which affects the quality of power supply and adds an electronic controller. The difficulty of anti-surge design.

In order to minimize the interference of the high-voltage discharge signal on the power supply and avoid electromagnetic coupling, the ignition device power input and high-voltage output are distributed on the corresponding two sides of the product shell, and the working current is transmitted in the forward direction when the power is turned on, and does not overlap; in addition, Maximize the distance between the input and output sockets, minimize the interference of high-voltage discharge signals on the power supply, and facilitate the design of product electromagnetic compatibility.

From the perspective of improving the quality of power supply, it is necessary to redesign the filter circuit, add a filter circuit on the power input end close to the ignition device, and select voltage regulator devices to improve the quality of the power supply. At the same time, a connector with better shielding performance is used, and the input and output cables are shielded. In addition, lightning protection design must be considered.

Sensor optimized design

According to different working principles, the sensors of the carrier engine are divided into platinum resistance temperature sensors, pressure sensors, thermocouples (collecting rings), speed sensors, vibration sensors, angular displacement sensors, ion flame detectors, and annunciator sensors. And so on, the corresponding optimization design of different types of sensors is also different.

Platinum resistance temperature sensors, rotational speed sensors, vibration sensors, angular displacement sensors, ion flame detectors and other sensors have their own working current of milliampere DC current, and the amount of electromagnetic emission is small. This type of sensor uses an all-metal housing to isolate the internal environment from the external environment. The different parts of the sensor that directly contact the external environment are welded by fusion welding, which can reduce the surface contact resistance as much as possible. Select wires, connectors and tail accessories with good shielding performance. According to previous test results, the sensor can meet the electromagnetic compatibility requirements of carrier-based aircraft engines.

The pressure sensor adopts a metal shell sealing design to isolate the internal environment from the external environment. The welding of different parts of the sensor directly in contact with the external environment should reduce the surface contact resistance as much as possible.

The thermocouple (snubber ring) adopts a metal shell seal design to isolate the internal environment from the external environment. The different parts of the thermocouple that directly contact the external environment are welded by fusion welding, which can reduce the surface contact resistance as much as possible, and has better The electromagnetic shielding effect. The slip ring used for signal transmission has no electromagnetic shielding structure outside the compensation wire, and its electromagnetic shielding ability is poor. The thermocouple uses the terminal as the signal output method, and the collector ring uses the terminal signal input method. The terminal and the metal body of the terminal are completely exposed to the electromagnetic environment. There is a risk of signal fluctuations during the electromagnetic assessment. It is necessary to consider shielding the connection mode of the thermocouple and the slip ring, and shielding the slip ring at the same time.

The annunciator sensors are all switching values. There are no electronic components inside the product, no components inside the product that are subject to electronic interference, and no components that emit electromagnetic waves. Based on past experience and bottom-out test results, the annunciator type can meet Electromagnetic compatibility requirements for carrier-based aircraft engines.

Concluding remarks

In order to meet the electromagnetic compatibility requirements of carrier-based aircraft engines, improve the electromagnetic compatibility of the control system and work reliability under complex electromagnetic environment conditions, in addition to the above optimization and improvement measures, it is necessary to further deepen the flight control coordination and coordinate the adoption of electromagnetic compatibility measures. According to the design requirements of electromagnetic environment effects of carrier-based aircraft engines, in view of other engine exposure problems and more stringent electromagnetic compatibility design requirements, signal loops should be analyzed, hierarchically classified and classified to achieve a more systematic electromagnetic compatibility optimization design.

(Xu Ming, Engineer, Major Special Equipment Project Management Center, Naval Equipment Department, mainly engaged in aviation equipment project management)
 

reservior dogs

Junior Member
Registered Member
I don't see a single WS-15 J-35 happening. I would prefer that carrier fighters enjoy the benefit of the safety redundancy of having two engines.

I can see a separate project, a speculative but logical stealthier successor to the JF-17 being powered by the WS-15 or WS-19. But that's another story.
How would this variant of J-17 be different from the J-10 in terms of capability? Wouldn't it be easier to just sell them J-10?
 

Deino

Lieutenant General
Staff member
Super Moderator
Registered Member
Pupu is pretty hit and miss regarding post 2010 PLAAF. I think it has to do with his original sources retiring.


So it is indeed a question how reliable and credible he still is and does SC really need to hang on a CAC-related date?
 

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