Chapter 509 happens to be the direction that Mr. Chang is paying attention to (10,000 per day, please give me a monthly vote~)
Liu Hongbo didn’t do much research on helicopters before, so he didn’t respond immediately, but turned his attention again Back to the computer screen.
The Z-9 is basically a 4-ton model, and its potential is relatively limited.
Of course, the Z-9 is currently the only type of helicopter that China can clearly build. The Z-8 introduced during the same period is even worse. Even the French themselves have completely given up on this model.
So there is no room for pickiness.
Moreover, the 4-6 ton class is indeed the largest class in the helicopter market. From this perspective, the Ice Flying Group's vision was indeed good.
Moreover, the planning of the four configurations is quite clear.
Needless to say the civilian model, the AS365 Dolphin, the prototype of the Z-9, already has a civilian model. It only needs to slightly improve the cockpit comfort and reliability to make it meet the current CAAC requirements for civil aircraft.
Of course there is a problem here, that is, when the airworthiness mutual recognition agreement was concluded with the EU and the United States, the mutual recognition objects were only "aircraft", that is, fixed-wing aircraft, excluding helicopters.
However, as long as it does not target the European and American markets, it is not a big problem.
This mutual recognition of airworthiness itself is equivalent to Europe and the United States recognizing China's strength in manufacturing small and medium-sized aircraft. For those third world countries whose airworthiness regulations are not strict, they actually have little energy to pay attention to those laws. difference.
The naval type is developed on the basis of the civilian type. At present, the basic design plan and prototype have been completed. The main difference is that in order to meet the needs of submarine search, patrol and search and rescue, the nose part A radome was installed.
This model is planned to be equipped with a turboshaft 8F engine with a power increased to 500kw, so as to at least be able to carry a suspended sonar and two anti-submarine torpedoes at the same time, or a suspended sonar, a sonar buoy and an anti-submarine torpedo. requirements.
For specific models with different functions, other equipment such as ultra-short hanging beams and electric winches can also be specifically modified.
But this is not a difference at the configuration level.
Generally speaking, the difference from the civilian type is relatively limited.
As for the assault transport type, which is the model that Liu Hongbo came to be responsible for this time, the design drawings are obviously only half completed.
However, we can already see the general ideas for improvement.
The overall design remains unchanged. The nose part is also elongated, but it is not used to accommodate radar. Instead, a photoelectric detection and targeting device is added below to provide the aircraft with the ability to use precision guided weapons. .
Additional reinforcements are made under the fuselage to install a set of curved beams for mounting weapons.
At the same time, this model will still retain the personnel transportation capabilities of the original Z-9, which can carry 4-6 fully armed soldiers and undertake transportation and combat tasks at the same time.
To this end, the take-off weight of the assault transport type will be increased to 5 tons, and the engine is also planned to be replaced with a 600kw-class improved turboshaft 8G
As for the final dedicated armed type, then There is not even a schematic diagram at the moment, only some textual descriptions.
Except for the ducted tail rotor, there are basically not many traces of the original model. Even the side-by-side cockpit has been changed to a tandem cockpit, and the landing gear has also been changed from the front three points with the main wheel behind. It became the last three points with the main wheel in front.
That is what Liu Hongbo mentioned before, changing from UH1 to AH1, or from Mi 8 to Mi 24.
For the Mi-24 and AH1, such changes are equivalent to redesigning everything except the engine and transmission system.
As for the Z-9, which is smaller and less powerful, a dedicated armed helicopter must have a take-off weight of about 6 tons, and even the power system must be changed...< br>
Relatively speaking, it is not a project that can produce results in a short time, so it is normal to put the priority later.
Basically equivalent to "a fan work that perfectly understands the spirit of the original work".
“This plan of yours…is not a small move.” After thinking for a while, Liu Hongbo finally commented.
Guo Jingshan waved his hand in embarrassment:
"Alas... after all, we are known as the cradle of the Republic's helicopter industry. We have to come up with something, right?"
"Especially the navy's anti-submarine helicopters and the army's armed helicopters. These are the equipment that the two services are most anxious to need. Now that the entire aviation industry is exploding, we at Ice Flying cannot just watch..."
Liu Hongbo went through the material he just read in his mind, and then said:
"The Z-9 is generally an aircraft with a relatively mature structure. You just said that you have improved the aircraft's defective transmission system in the past, so what we need to assist should be the structural reinforcement of the assault transport model, and also There is... research on rotor flow field and noise characteristics?"
"Yes"
Guo Jingshan nodded:
"The previous Z-9 was mainly. The solution is to solve the problem of helicopter availability. The requirements for performance are not high, but now these four configurations cannot be sloppy, especially the hovering stability, as well as the vibration and noise during flight, which have a negative impact on the survivability and performance of the aircraft. "We have previously conducted tests with the Navy's AS565 Panther anti-submarine helicopter imported directly from France, and found that it cannot maintain a stable hover for more than two minutes even in level 4 sea conditions. Stop, and the noise level in the cabin will have a significant adverse impact on search and attack submarine operations.”
"The original French products are all like this, so the Z-9A that was copied before will definitely not meet the requirements, so our plan is to keep the transmission mechanism unchanged, but redesign the fuselage and rotor, but..."
Speaking of this, Guo Jingshan showed some embarrassment on his face:
“However, our technical strength in this area is really limited. Even in developed countries, helicopter acoustic research has only been done in the past two years. Starting a new field of application, so...I wanted to find your help."
"Rotor calculation is indeed a problem."
Liu Hongbo turned his chair and faced Guo Jingshan:
"Due to the rotation of the blades, when the helicopter flies forward at high speed, shock waves may exist on the forward rotor blades. If the shock waves are strong, they will expand to areas outside the blade radius, which will have a strong impact on the flow field. . ”
“In addition, when the angle of attack is large, interference from shock waves and boundary layers may occur; in hovering, low-speed forward flight, and low-ground flight conditions, the blade tip may become dislodged. The vortex cannot leave the rotor quickly, and the tip vortex will dominate, which is very different from a fixed wing, even a propeller-powered fixed-wing aircraft."
Seeing Liu Hongbo come up and analyze the difficulties, Guo Jingshan thought. He was asking for a longer time, and immediately said with relief:
"We are still relatively loose in setting the timetable. The assault transport type and the naval type are planned to first fly before 2001, and the special purpose Armed type... There is no specific progress plan yet..."
Obviously, Bingfei is very aware of his own situation and has not made any ambitious plans.
However, perhaps because he has followed Chang Haonan for a long time, Liu Hongbo is somewhat dissatisfied with such a conservative plan:
“2001 was too slow, this is not feasible...”
“Ah ?”
Guo Jingshan was immediately confused.
“Rotor calculation is a typical unsteady flow problem, which happens to be our recent focus of research.”
Liu Hongbo continued:
"In addition, I already have some ideas about sound field calculations, but I am not sure about the feasibility. I will consult Mr. Chang tomorrow morning."
"Anyway, we will do this today. Install the latest version of TORCMultiphysics overnight and start working as soon as possible! ”
(End of this chapter)