Liu Hongbo didn't have much research on helicopters before, so he didn't respond immediately, but once again turned his attention back to the computer screen.

The straight 9 base should be a 4-ton model, and the potential is relatively limited.

Of course, the Z-9 is the only helicopter that Huaxia can make at present, and the Z-8 introduced during the same period is even worse, and even the French themselves have completely abandoned this model.

So there's no room for picking.

Moreover, the 4-6 ton class is indeed the largest class in the helicopter market, from this point of view, Bingfei Group's vision back then was really good.

Moreover, the planning of the four configurations can be regarded as well-organized.

Needless to say, the prototype AS365 Dolphin of the Z-9 already has a civilian model, as long as the cockpit comfort and reliability are slightly improved to meet the current CAAC requirements for civil aircraft.

Of course, there is a problem here, that is, when the airworthiness mutual recognition agreement was signed with the European Union and the United States, the mutual recognition object was only "aircraft", that is, fixed-wing aircraft, excluding helicopters.

However, as long as it is not oriented to the European and American markets, it is not a big problem.

This act of mutual recognition of airworthiness itself is equivalent to Europe and the United States recognizing China's strength in the manufacture of small and medium-sized aircraft, and for those third world countries whose airworthiness regulations are not strict, there is actually little energy to pick out those legal differences.

The naval version is developed on the basis of the civilian version, and the basic design scheme and prototype have been completed, the main difference is that in order to meet the needs of submarine search, patrol and search and rescue, a radome is installed in the nose part.

This model is planned to be retrofitted with a turboshaft 8F engine in the 500kw class to meet the requirements of carrying at least one sonar and two anti-submarine torpedoes, or one sonar, sonar buoy and one anti-submarine torpedo.

For the specific models with different functions, other equipment such as ultra-short hanging beams and electric winches can also be specifically modified.

But that's not a configuration-level difference.

In general, the difference from the civilian type is relatively limited.

And the assault transport type, that is, the model that Liu Hongbo came to be responsible for this time, the design drawing is obviously only half completed.

However, we can already see the general idea of improvement.

The overall design remains the same, the nose part is also extended, but instead of accommodating the radar, an optoelectronic detection and targeting device is added underneath to provide the aircraft with the ability to use precision-guided weapons.

Additional reinforcement was 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 transport capacity of the original Z-9, which can carry 4-6 fully armed soldiers and take on both transport and combat missions.

To this end, the take-off weight of the assault transport version will be increased to 5 tons, and the engine is also planned to be replaced with an improved turboshaft 8G in the 600kw class

As for the final special armament type, there is not even a schematic diagram at the moment, only some text descriptions.

In addition to the ducted tail rotor, there are basically not too many shadows of the original model, and even the parallel cockpit has been changed to a tandem cockpit, and the landing gear has also been changed from the front three points of the main wheel to the rear three points of the main wheel.

That is, Liu Hongbo mentioned before, from UH1 to AH1, or from Mi8 to Mi24.

For the Mi-24 and AH1, such a change is equivalent to a complete redesign of all parts except the engine and transmission system.

For the Z-9, which is smaller and weaker in power, the special armed helicopter must have a take-off weight of about 6 tons, and even the power system needs to be changed......

Relatively speaking, it is not a project that can produce results in a short period of time, and it is normal to prioritize it later.

It's basically equivalent to "a fanwork that perfectly understands the spirit of the original.。

"Your plan...... It's not a small move. ”

After thinking for a while, Liu Hongbo finally commented.

Guo Jingshan waved his hand a little embarrassed:

"Alas...... After all, we are known as the cradle of the helicopter industry of the Republic, and we have to shake something out of it, right? ”

"Especially the anti-submarine helicopters of the Navy and the armed helicopters of the Army, these are the most urgent equipment of the two services, and now the entire aviation industry is exploding, and it is impossible for us to watch it on the ice......

Liu Hongbo probably went through the materials he had just finished reading in his mind, and then said:

"The Z-9 is generally a relatively mature aircraft, and you just said that you have improved the transmission system of the aircraft that was defective in the past, so what we need to assist should be the structural reinforcement of the assault transport model, and the ...... Rotor flow field and noise characteristics? ”

"That's right."

Guo Jingshan nodded:

"The previous Z-9 mainly solved the problem of whether the helicopter existed, and the requirements for the performance level were not high, but now these four configurations can not be sloppy, especially the hovering stability, as well as the vibration and noise during the flight, which have a very fatal impact on the survivability and performance of the aircraft."

"We have previously tested the AS565 Panther anti-submarine helicopter imported directly from France by the Navy, and found that it cannot maintain a stable hovering for more than two minutes even in level 4 sea conditions, and the noise level in the cabin will have a significant adverse impact on the search and attack submarine operation."

"The French originals are all like this, and the straight 9A that was copied before is definitely more unsatisfactory, so our plan is to keep the transmission mechanism unchanged, but redesign the fuselage and rotors, but ......"

Speaking of this, Guo Jingshan showed some embarrassment on his face:

"However, our technical strength in this area is really limited, and the acoustic research of helicopters is a new field that has only begun to be applied in the past two years, even in developed countries, so it ...... I just wanted to find you for help. ”

"Rotor calculations are really a problem."

Liu Hongbo turned his chair and made himself face Guo Jingshan:

"Because of the rotation of the blades, when the helicopter flies forward at high speed, there can be shock waves on the forward blades of the rotor, and if the shock waves are strong, they will also expand to areas beyond the radius of the blades, which will have a strong impact on the flow field."

"In addition, when the angle of attack is large, shock waves and interference of the surface layer may occur; In hovering and low-speed forward flight and near-ground flight, the propeller tip vortex cannot quickly leave the rotor, and the propeller tip vortex will dominate, which is very different from fixed-wing aircraft, even propeller-powered fixed-wing aircraft. ”

Seeing Liu Hongbo come up and analyze the difficulties, Guo Jingshan thought that he was asking for a longer time, and immediately relieved:

"We are still relatively relaxed in the timetable, and the plans for the assault transport type and the naval type are both to make their first flight before 2001, and the special armed type...... There is no concrete schedule yet......"

Obviously, Bingfei has a very good B number for his own situation, and he has not set a plan to be ambitious.

However, perhaps because he has been following Chang Haonan for a long time, Liu Hongbo is a little dissatisfied with such a conservative plan:

"2001 was too slow, it didn't work......"

"Huh?"

Guo Jingshan was directly stunned.

"Rotor calculation is a typical unsteady flow problem, which happens to be the research direction that we have focused on recently."

Liu Hongbo continued:

"In addition, I already have some ideas about the sound field calculation, but I am not sure about the feasibility, so I will consult Mr. Chang tomorrow morning."

"Anyway, let's install the latest version of TORCH Multiphysics overnight today, and then start working as soon as possible!"

(End of chapter)