Chapter Nineteen Worth It
If humans didn't have a heart, would life still be able to continue? If cars didn't have an engine, could the journey still go on? If planes didn't have an engine, could flight still continue? Every thing, whether it has life or not, has its own core. Humans can't live without a heart, and planes can't fly without an engine; they all rely on their own core.
Yulin in Guangxi is a very important industrial city in the autonomous region. The reason why it is so important is that the things researched and produced here are all indispensable cores. AVIC XAC in Yulin is not one of the largest in scale, but the number of high-end talents and the scientific and technological content of products are undoubtedly the highest, because their work is to research and produce aero engines.
The Taishan Plan brought an unprecedented opportunity to the company, with more than a dozen exclusive research laboratories in the depths of the nine major mountains. Because they are application-oriented research, a considerable part of the departments in the Taishan Plan will serve them with all their might, especially the jet engine series research project, which is one of the core parts of the Taishan Plan.
"The research and development of aircraft engines has its own characteristics, with high technical difficulties, large capital consumption, long research cycles, and no end in sight. However, we must consider that the engine has a decisive impact on the success or failure, progress, and performance of aircraft development. Moreover, engine technology has good military-civilian dual-use characteristics, which are of great significance to national defense and the national economy. Aircraft engines are extremely critical and valuable scientific and technological secrets. We can only maintain our advantage in this field by persisting in the research and development of more advanced, reliable, and practical aircraft engines."
Zhang Yu's requirement for China Aviation Power Company and the Taishan Plan Jet Engine Research Project Team is just this short paragraph, although the words are few but the meaning is very clear, that is, at all costs, without fear of any hardship or suffering, to make the development of aero engines a glorious undertaking that requires long-term struggle. In fact, knowing that this aspect has great prospects, they are indeed doing so, even if the Taishan Plan was not implemented, China Aviation Power had already conducted relevant research, and later with the support of the lavish plan, their progress became even faster.
The autonomous region currently has aircraft, including the C-01 "Blue Eagle" used for military-civilian dual development, the Z-01 "Bamboo Dragonfly" helicopter that participated in the Haiyuan earthquake relief efforts, the "Flying Eagle" fighter jet, the "Flying Bird" torpedo bomber, and the "Flying Swallow" dive bomber. There is also a biplane trainer called the "Chick". Six types of aircraft with over ten derivative models all use piston engines, which still have great development potential. The air force, naval aviation, and civil aviation all require better-performing piston engines. For example, Southwest Civil Aviation would naturally prefer larger-capacity, longer-range aircraft. The air force and naval aviation also hope for better aircraft to emerge, although they do not urgently need them at present.
Customers have potential needs, but no actual orders. The aviation market is limited to domestic only. China Aviation's three major groups are trying their best to think of ways to win more market orders. However, the demand from air force, sea navigation, and civil aviation enterprises is limited. To absorb more nutrients for growth and expansion into a wider overseas market is the only way out. They repeatedly persuade the civil aviation management department to relax restrictions on this aspect, allowing planes to be exported as well. Of course, they also haven't forgotten the urgent need to develop better planes, participate in the Mount Tai plan to enhance scientific research strength and technical reserves.
The development of aero engines involves support in many aspects. In terms of aviation materials, the material requirements for jet engines are far higher than those for piston engines, and more precise processing techniques are needed to support them, faster data analysis is needed as a backing, and more complete equipment is needed for experimentation. The development of aero engines is an important part of the plan, and naturally received enough attention from the very beginning. Under the care of all the stars, this project will eventually achieve results, after all, heaven rewards diligence.
November 5, 1921, Zhonghang Power Co., Ltd. was established as an independent company, and its "Independent Research" plan was approved by the Ministry of Industry, starting research on turbojet, turboprop, turboshaft, and other aspects. On December 5, 1923, under the promotion of the Taishan Plan Preparatory Committee, the main research institution of the company was officially incorporated into the Taishan Plan Aviation Engine Research Project Group, and piston engines also became an independent research direction.
After nearly five years of hard work, the project team finally achieved a better result.
"An axial flow turbojet engine, from front to back, has an inlet, compressor, combustion chamber, gas turbine, nozzle, afterburner, fuel injector, and variable area nozzle. A centrifugal flow engine has a centrifugal compressor, combustion chamber, turbine, and finally the exhaust system. The turbopropeller is similar in construction to the turbojet except that it has a reduction gear and propeller; the turboshaft is also similar but with a fan and low-pressure turbine driving the fan and high-pressure turbine driving the compressor."
"In addition, the turbine shaft engine consists of parts and working processes that are actually very similar to those of a turboprop engine. The only difference is that almost all of its energy is converted into shaft power, which then drives the helicopter's rotor and tail rotor through a gearbox. Our current work has resulted in the development of the first turbojet engine, which is what we see here today. We have given it a meaningful name: Taishan."
The quiet engine lying in front of Zhang Yu is the result of the project team's hard work for more than five years. The turbojet engine can be considered as the foundation of the entire jet engine series, just like what Wang Zhuo said earlier, the turbine impeller, turbine shaft and turbine fan can all be studied based on it.
"Air enters the engine through the inlet, slows down and increases pressure. The compressor can boost air pressure several times to tens of times, allowing high-pressure air to enter the combustion chamber, mix with fuel sprayed from the nozzle, and burn. The high-temperature and high-pressure gas produced by combustion drives the turbine to work at high speed, producing a large amount of mechanical energy, which in turn drives the compressor and other accessories to work. Moreover, the exhaust gas from the turbine directly expands in the nozzle, converting the available energy of the gas into kinetic energy of the high-speed jet flow, generating a huge reaction force. This is also the working principle of this engine."
The air intake is the engine's air inlet, which organizes airflow, eliminates vortex, and ensures that the engine can provide the required amount of air in various working conditions, especially during high-speed flight. The function of the air intake is particularly important to slow down the high-speed airflow and convert the kinetic energy of the airflow into pressure potential energy.
The compressor is a very important component in the engine, and its function is to increase the air pressure entering the combustion chamber. The principle is to use high-speed rotating blades to work on the air. It is divided into two types: centrifugal and axial flow. However, the boost ratio of the centrifugal type is not high enough, less than ten times, and the centrifugal impeller is too large, so it can only be used for small-power engines. The axial-flow compressor composed of stator (diffuser) and rotor does not have this problem.
The stator and rotor are composed of multiple rows of blades, with the blades arranged in a staggered manner along the axis of the compressor. The inlet of the compressor is large and the outlet is small. Moreover, the pipe wall of the stator looks like it has many deep grooves, while the rotor looks like a long stick full of small knife-like protrusions.
The rotor blades are in the front and the stator blades are in the back. The mutual movement between them forces the air coming from the intake to be continuously compressed. Every time the air passes through a level of rotor blades, its pressure, speed, and temperature increase. After deceleration, compression, and rectification by a level of stator blades, it enters the next level of rotor blades. Therefore, in order to obtain a higher compression ratio, single-stage compression is not feasible. Multiple stages are combined to form a multi-stage axial compressor, with a low compression ratio of three to five, and a high one can reach twenty or thirty, or even forty or fifty. However, the compression effect is very good, but the processing of stator and rotor is extremely troublesome. Without high-precision machining equipment, it is impossible to make "wolf-toothed bars".
Testing a country's industrial strength is not just about static and dynamic, but also the combustion chamber is one of the most important components of an engine. After the air is compressed by the compressor to form high-pressure and high-temperature air, it enters the combustion chamber, where it will burn with fuel, causing the temperature and pressure of the gas to surge, finally forming high-temperature and high-pressure air that rushes towards the turbine.
The combustion chamber has a casing, flame tube, nozzle and vortex generator. The gas coming from the compressor is divided into two parts: a small portion of the gas flows into the flame tube head and its small holes to mix with fuel for combustion, while most of the gas must flow backwards along the channel between the flame tube and the casing to cool the flame tube wall, so as not to make the flame tube wall temperature too high, causing the turbine to burn out due to overheating. However, even so, the temperature in the combustion chamber is still quite terrifying. If the material processing is not good enough, it is absolutely impossible to make a good engine. Even if it is made, it cannot achieve excellence and practicality in terms of usage time and working life.
The function of the turbine is to convert the high-temperature and high-pressure gas energy at the outlet of the combustion chamber into mechanical energy. The fuel gas ejected from the combustion chamber impacts the turbine, causing the working wheel to rotate at high speed, and the mechanical energy is output in the form of shaft power, driving the compressor, fan, propeller or other accessories to work. After passing through the turbine, the temperature and pressure of the high-temperature and high-pressure gas have decreased significantly, and the speed has increased greatly, producing thrust after passing through the convergent nozzle.
The composition of the turbine is actually similar to that of a compressor, with stationary guide vanes and rotating working blades being its key components. Both have many blades installed radially, their channels are all convergent, bearing high-speed high-temperature high-pressure airflow continuously impacting, making high-speed rotation movements of several thousand revolutions per minute, tens of thousands of revolutions per minute, so the working blades must withstand great centrifugal force, and must have good high-temperature resistance and corrosion resistance properties.
"The thrust of the engine is related to the temperature of the gas before the turbine. The higher the temperature, the greater the thrust, but the heat resistance of the turbine blade material is limited, and even with cooling measures, it can only increase the limit to around 1200 degrees Celsius. Simply increasing the temperature of the gas to increase thrust is not feasible. However, there is still a lot of oxygen in the high-temperature gas flowing through the turbine, and there are no moving parts restricting the temperature rise in this section. By adding a combustion chamber behind the turbine to burn fuel again, the temperature can be increased to around 1700 degrees Celsius. With this reheat combustion, the energy and exhaust speed of the gas will increase significantly, and without changing the working state of any other components, it is possible to achieve an increase in thrust of over 20%, or even higher. Of course, the problems of excessive fuel consumption and high temperature are also not to be ignored..."
"Our engine is expected to have a thrust of 8,000 kilograms, or 800 daN. The thrust-to-weight ratio is expected to be around 2.7. After one inspection, we will conduct the first test run. In addition, research on turbofans, turbopropellers, and turbo-axles has made great progress, and it is expected that trial products will be produced in batches by next March. Research work on related flight models has also been launched. If this engine can complete all tests and experiments smoothly, the first jet aircraft will make its maiden flight around 2030."
"This schedule is quite tight!" Zhang Yu smiled and patted the Tai Shan engine, saying: "All along, aviation technology development has been mainly focused on aircraft engine research, while computer technology development has been mainly focused on integrated circuit technology research. The Tai Shan project attaches great importance to these two major projects, except for biopharmaceuticals and other fields that have not been involved, all other departments have been pulled in. Your requirements are the driving force behind their progress, just like this engine in front of us, what kind of materials do you want, what mechanical properties must be achieved, other research institutions will try to meet them, including the computer technology development project team."
"This issue is not something we can control, without their support, we cannot make progress."
From returning to the country until now, Wang Zhuo has walked a long way, from the chief designer of the aircraft to the current leader of the jet engine project team. His growth process, apart from being described as overwork and staying up all night, is more about continuous learning and practice. The success of the piston aircraft with low technical requirements and difficulty does not mean that the jet aircraft can continue smoothly. To achieve results, one has to work hard with their head down, and this is the purpose of the Mount Tai plan.
"I'm really looking forward to you developing a better engine, with a higher power-to-weight ratio and efficiency, longer lifespan, and lower fuel consumption." Zhang Yusheng could only offer these words of encouragement after listening for a long time. He couldn't say anything more, nor could he utter any technical jargon. Meanwhile, in another part of the autonomous region, something rich in technology was born.
Located in Guizhou, China Aviation Industry Second Group developed in some remote areas of Guizhou because their production and research products require a certain level of secrecy. The military's dive bombers, torpedo bombers, and fighter jets are all produced by this group. In the development of helicopters, the group has strong capabilities, with the Z-01 "Bamboo Dragonfly" helicopter being their first work.
The Z-01 "Bamboo Dragonfly" helicopter, which made its first flight in April 1922 and was finalized for production by the end of 1923, is equipped with a supercharged piston engine. The aircraft has a very simple structure, with an empty weight of 858 kg and a takeoff weight of 1340 kg. Its maximum speed is 160 km/h, with an economical cruising speed of 135 km/h and a range of 400 km. Fifteen helicopters flew over 1,000 sorties during the Haiyuan earthquake, each capable of carrying three passengers or 150 kg of cargo. During rescue operations, they often carried one stretcher and one medical personnel.
The WZ-10 played a very good role in the rescue mission, but as a single-pilot light helicopter, its civilian value is not great and its military prospects are limited. Its load capacity is limited, and its fuselage is not strong enough to carry a soldier operating a heavy machine gun with some ammunition, which may be one of its main uses. Of course, it can still be used for reconnaissance. In short, the army has little use for it, and the order quantity is small. Moreover, the government has strictly ordered that no aircraft be exported from the autonomous region at present. Therefore, if China Aviation Second Group wants to make helicopters a strong selling point, they need to come up with better helicopters.
The helicopter, codenamed "Whirlwind", is a multi-purpose helicopter development plan made by AVIC II after sorting out military demands and the pros and cons of the WZ-19. It is equipped with a 1250 kW air-cooled radial piston engine, with a main rotor diameter of 21 meters, length of 16.8 meters, and height of 4.4 meters. The landing gear is fixed four-point type, with a front wheel track of 1.53 meters, main wheel track of 3.82 meters, and front-rear wheel distance of 3.79 meters. The cabin volume reaches 16 cubic meters, with one side door and one clamshell rear door.
The engine compartment is located at the front of the aircraft, driving the main rotor on top of the cabin and the tail rotor at the rear through a transmission shaft. The cockpit is located in the front upper part of the fuselage, with a crew of two, both capable of independent flight control. It can carry 1.2 tons of cargo, or 1.35 tons when sling-loading. The spacious cabin can accommodate 11 fully armed soldiers, or eight stretcher cases plus one medical attendant, and can also be used to transport a jeep or for material transportation.
It can be said that this helicopter is the second aviation group of China Aviation, which was specially developed for the military. Currently, only the military will be the largest procurement unit of this group. Therefore, the multi-purpose helicopter launched by this research plan is a versatile all-rounder. The military can modify it into many derivative types based on this platform, which can be used for material and personnel transportation, armed attack, casualty rescue, reconnaissance patrol, etc. The rapid reaction brigade stationed in Liuzhou is very concerned about the progress of this aircraft.
However, the CAAC Second Group was not aware that this type of helicopter is the best and also the last among all piston helicopters. The future of using piston engines on fixed-wing aircraft far exceeds that on helicopters, and it is the turboshaft engine that truly belongs to helicopters that makes large-scale application possible.
Zhang Yu and others were on their way back to Liuzhou from the Taishan Plan base group when they learned that the "Whirlwind" helicopter test flight had been successful. The autonomous region's aviation industry has developed very well and quickly, and in comparison, industries such as industry, agriculture, and commerce are also not to be underestimated. The continuously increasing comprehensive strength gives the People's Autonomous Government more confidence and ability to solve some problems that should be solved, such as Hong Kong.
