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This is also the reason why Dennis had no choice but to ask Lydia and others to assist him. Although these halflings do not know magic, they are very strong and have good engineering talent. They are always useful when doing odd jobs or assembling instruments.
"It's a pity that it's a little late. It would be perfect if it could be completed before this year's academic seminar!" Dennis said regretfully.
Otherwise, it is certain that you will receive a Morning Star Medal for your research!
"It's not too late. Once you have completely perfected the jet fighter, you will be able to catch up with next year's academic seminar." Lin En said with a smile, and then looked at the thrusters that had turned red and showed signs of melting, but were still emitting flames, and gave a reminder.
"Master Dennis, I wonder if you have ever thought about further increasing the speed of the air jet by changing the internal structure of the thruster..."
Since Dennis has already developed the prototype of the jet propulsion device, Lynn naturally no longer hides it.
How can a jet plane reach a speed of 700 kilometers per hour?
Even three or five times the speed of sound is just the beginning!
You have to know that this time they are preparing for a cross-border war. No matter how much they overestimate the enemy, it is not an exaggeration. They must go all out and make as many preparations as possible.
A supersonic fighter is not much slower than a legend in terms of speed. If it can be equipped with a device that can launch the Eternal Flame or even a small fusion bomb, it should be able to pose a considerable threat to the legend.
Still increasing? The wizards present all looked at Lin En with strange eyes, and Tim was completely stunned. In his opinion, 700 kilometers per hour was already a very terrifying speed, and one day was enough to travel across the empire several times.
Dennis was extremely excited. He had certainly considered increasing the speed by changing the shape of the gas chamber. In fact, he had already done a lot of experiments.
For example, he made some improvements to the third air chamber of the thruster, which can eject the high-temperature and high-speed airflow caused by the hydrogen-oxygen mixture explosion to the greatest extent, greatly reducing the possibility of explosion.
In order to help Lynn see more clearly, Dennis walked straight forward, stopped the thruster and disassembled it, explaining the internal structure design one by one.
Although every structural improvement was the result of dozens or even hundreds of experiments, Dennis had no intention of hiding anything in front of the Magic Star and explained everything in detail, from the design concept to the problems that arose in actual application.
After all, Lin En was very generous and directly took out the drawings of the internal combustion engine and let Dennis do some research on it. Dennis didn't think that the other party would do anything to steal the results of the magic research.
After listening to Dennis's story, Lynn pondered for a moment and quickly spoke.
"You designed a three-gas chamber structure that is very good. You use the property that highly pure hydrogen and oxygen cannot be ignited alone to block the reflux of high-temperature gases generated by combustion. However, this is not safe enough..."
"I suggest that you add a step to compress the gas in the front half of the third gas chamber. This will not only further increase the power provided by the gas combustion and eruption, but also create a pressure difference between the front and back, which will serve as a second insurance..."
Combining the design concept of the jet turbine engine, Lynn explained to Dennis how to use multiple rotating and fixed blades that form a V-shaped structure to compress the produced fuel gas multiple times and send it into the combustion chamber.
"But, in this case, wouldn't the danger of this thruster be even greater?" Tim couldn't help but interrupt. He felt that this Magic Star was just giving some bad ideas.
The previous multiple explosions of the thrusters were due to the fact that the high-temperature airflow generated by the hydrogen-oxygen combustion reaction was too strong, which directly blew through the gas chamber. If the density of the fuel gas is increased again, the thrust generated during combustion will be stronger, but the possibility of accidents will also be higher.
"That's because the steel used to make it has poor pressure and heat bearing capabilities. If the key parts are replaced with stronger alloys or mithril, this level of pressure will be nothing." Lin En shook his head, took the blueprint on the table, and continued to speak while drawing.
"Also, Master Dennis, the heat dissipation of your thrusters is also a big problem. I suggest that you design the combustion chamber into an embedded structure and open a few vents to directly use the high-speed airflow around the fighter plane when it is flying to cool it down."
"Wonderful, what a great idea..." Dennis said excitedly. Originally, he was planning to fill the outside of the combustion chamber with low-temperature liquid to achieve the cooling effect, but Lynn's design was obviously more energy-efficient because the wind came directly from the airflow when the fighter was flying.
Lin En scribbled and added many ideas into it. The thruster, which was modified many times, looked like a patchwork monster.
But as long as it is useful and efficient!
Come however is convenient!
"Why does this thruster structure look so strange?" Dennis glanced at Lynn's improved drawings and asked in confusion.
It looks like two funnels, front and back, with the narrow parts connected together.
"This is the structure I recently researched. It's the most consistent with fluid mechanics. It's expected to double the flow rate of gas and liquid through the pipeline!" Lynn's mouth curled up into a smile, and he explained that this structure is actually the famous Laval tube, also known as a transonic nozzle.
Dennis couldn't help but frown as he looked at the blueprint. He believed that the speed could be increased by optimizing the thruster pipe structure, but it was a bit too exaggerated to double the original speed just by changing a structure.
You know, the original speed of his explosive thrusters can reach 700 kilometers per hour, and after the step of compressing the gas, its speed will only be faster!
What kind of concept is it that it can continue to double on this basis?
Dennis really couldn't imagine it, and couldn't figure out what was so special about the trumpet-shaped structure in front of him that could play such a big role.
“Whether it works or not, we’ll know if we just give it a try,” Lin En said with a smile. He was also very curious about what this suture thruster in front of him could do.
Dennis nodded, without further ado, rolled up his sleeves, and immediately began working on improving the thrusters.
Lin En was not idle either. He was personally responsible for making the third gas chamber that needed to withstand pressure, and even called Tim who was idle nearby.
The great wizard possesses atomic-level control capabilities and can manipulate, analyze, and mimic almost all elements except special elements. His use in engineering can only be described as efficient.
Even with the engraving of the alchemical array, the modification of the new thruster was completed within two hours.
Now it’s time to experiment!
A group of alchemists and halflings like Darren immediately evacuated to a safe area. Perhaps because he had participated in the production, Tim did not have such a big psychological barrier this time.
Dennis carefully placed his hand on the magic transmission device, and with the rapid influx of magic power, the thrusters were activated again.
A huge explosion soon rang in everyone's ears, and then a red tail flame shot out from the nozzle behind the thruster.
The platform below that was used to fix the thrusters was shaking continuously. If it hadn't been reinforced by Lin En, the thrusters would have flown out in an instant!
"What a strong tail flame..." Dennis said in amazement. The high-temperature flame shooting out from the nozzle was gathered into a two-meter-long jet flame column, which was even longer than the thruster itself!
Even with the naked eye he could see that the thrust provided by this thing was several levels higher than before.
Under everyone's gaze, the scale on the thrust detection device continued to rise...
Six hundred, seven hundred, eight hundred, nine hundred… and then it got stuck there and couldn’t move.
"Master Dennis, I'm afraid it has exceeded the limits of our detection!" said an alchemist in fear.
This means that the maximum speed of the jet stream is over one thousand kilometers per hour!
After more than ten seconds of accumulation and acceleration, the shape of the high-temperature airflow ejected from the nozzle changed again. The flame near the nozzle was slightly concave. The fire flow in this area was much brighter than the rest, in a circular shape, and trembling slightly...
Without waiting for anyone to ask, Lin En took the initiative to explain. "This is a sonic ring, which means that the speed of the airflow exceeds the speed of sound!"
The supersonic air flow pressure is very high, so when it is sprayed into the air from the nozzle, it will expand rapidly, but the air flow pressure after expansion will be significantly lower than the atmospheric pressure, so it will be compressed again.
In this way, the supersonic airflow will cycle back and forth between expansion and compression. This process will form expansion waves and compression waves. The two meet and superimpose during the propagation process, forming circular rings on the thruster tail flame, which are the so-called sonic rings or Mach rings!
This colorful sonic ring looks particularly obvious because the steam flow formed by the burning hydrogen and oxygen mixture increases the humidity of the nearby air.
"One ring represents double the speed of sound!" Lin En looked at the surging tail flame, and the second sonic ring did not appear. "It's a pity that it still can't reach double the speed of sound, but I think it should be very close..."
According to his expectations, after the gas compression step, the high-temperature airflow released during combustion would be able to reach subsonic speed before entering the Laval tube. After two accelerations before and after passing through the Laval tube, it should be able to reach about twice the speed of sound. Unfortunately, it was still a little short in the end.
"Speaker Lin, do you mean that the speed of the high-temperature air flow is now over two thousand kilometers per hour?" Tim said in disbelief.
Although the speed of sound propagation will vary depending on the air pressure and temperature, on average it is about 340 meters per second, or 1,200 kilometers per hour!
And nearly twice the speed of sound means more than 2,000 kilometers per hour...
Tim was amazed. What kind of monster were they going to create?
Even Dennis found it a little hard to believe. Even though he had guessed before that after their modification, the power of the thrusters would definitely be qualitatively improved, he had not expected it to be so fast.
"Dean Lin, can you fly that fast?" Lydia asked curiously.
"Not yet..." Lin En shook his head. His flying speed was about 1.5 times the speed of sound.
"Doesn't that mean that as long as I'm flying this fighter, even the legendary wizard won't be able to catch up with me?" Lydia said expectantly.
"That's hard to say." Lin En laughed, and in case Lydia was too confident, he poured cold water on her. "Some magic is very fast. For example, my electromagnetic railgun can reach more than 20 times the speed of sound. If it were a laser beam, you probably wouldn't even have a chance to dodge it."
Lydia thought about the scene of herself flying a fighter plane and being pointed at by several laser beams, and she shrank her neck immediately.
Lynn asked Dennis to stop the operation of the thruster, disassemble it again to find out which part affected the airflow speed to reach the limit, and continued to improve the internal structure.
"Need to change more?" The corners of Tim's mouth twitched involuntarily. Such a fast speed made him feel a little scared. It was completely beyond his imagination.
In the past, the speed of sound was a realm that only legends could reach, which meant breaking the sound barrier and transcending the limitations of nature.
In his opinion, this speed was fast enough!
"It's only close to twice the speed of sound, and it's far from the limit of jet propulsion!" Lynn said with a smile.
For a jet fighter, three times the speed of sound is not much, five times the speed of sound is acceptable, and ten times the speed of sound is considered qualified...
"In addition, the fighter's appearance also needs to be further optimized. Supersonic speed and subsonic speed are two completely different concepts. A fighter flying at super-high speed will accelerate the flow of the surrounding air, compress the gas, and form a shock wave surface at the windward side of the aircraft..."
Lynn explained to Dennis the various obstacles that fighter jets would encounter when flying at high speeds, and drew out the design drawings of a simple wind tunnel in order to simulate the airflow conditions during supersonic flight.
Chapter 530: Graphene Shield and Mass Production of Chlorine Trifluoride
"Okay, that's all I have to say about the improvement plan for the new fighter's appearance." Lin En described the outer shell shapes of several of the Federation's most advanced fighters, of course, using his research on fluid mechanics as an excuse. Then he asked Dennis and others to build a wind tunnel first, conduct preliminary experiments on the ground, and consider actual flight after confirming that there are no problems...
Supersonic fighter jets are extremely fast and do not allow the slightest error. If the appearance design is not reasonable, breaking the sound barrier when going at the speed of sound will become a fatal blade, causing the fighter jet to lose balance or even tear the fuselage, resulting in a very horrific air crash.
However, Lynn has full confidence in the research and development of supersonic fighter jets, because he has avoided most of the problems that will be encountered in the design, which is equivalent to directly announcing the correct answer, saving decades of research and improvement time.
This is undoubtedly a bit of a hasty move. If the parliament was not facing a cross-border war, Lynn would not have directly shown the most perfect fluid mechanics structure to Dennis. After all, correcting mistakes is itself a very valuable experience.
Dennis memorized the several design drawings drawn by Lynn firmly in his mind, and Lydia and others were no exception, because the shapes and structures of the aircraft on these drawings looked extremely beautiful and pleasing to the eye, they were simply works of art!
Tim hesitated for a while before speaking with concern, "Chairman Lin, if the speed of the fighter planes continues to increase, will the pilots inside find it unbearable or unable to react quickly in battle?"
"You underestimate the limits of what humans can achieve. As long as we undergo appropriate training, it won't be a big problem to withstand high pressure that is several times the acceleration of gravity." Lynn explained.
Before federal researchers deciphered the genetic modification technology, the pilots of supersonic fighter jets were selected from ordinary people. Since they had no problems, let alone wizards with better physical fitness and quicker reaction abilities!
The only thing that needs to be considered is how the fighter pilot can distinguish between friend and foe while flying at high speed.
On the technological level, radar is usually used to solve the problem, but this is obviously not safe enough because the opponent may have some means of shielding or interfering with the electromagnetic field.
So Lin En plans to add another layer of insurance. Based on the position of each fighter plane, he will build an airspace network that can sense magic power, and use the magic network link of the intelligent brain to achieve real-time information sharing and distinguish between friend and foe.
During the battle, the targets in the air and connected to the magic net are our own people, and the rest are enemies that need to be dealt with.
"In this way, we don't have to worry about the most critical problem of detecting the enemy." Dennis nodded, and then continued to ask, "Then should we engrave a windproof magic circle on the outer shell of the fighter plane as usual to slow down or eliminate the impact of the shock wave..."
"No, there is no need for the wind-proof magic circle. Instead, it will increase the wind resistance of the fighter plane, thereby reducing its speed..." Lin En shook his head.
Although windproof magic is easy to use, its operating principle is to create a cone-shaped, constantly flowing magic barrier in front, thereby achieving the effect of separating the airflow. It is very useful when flying at low speeds, but not at high speeds.
Because the output speed of magic power cannot keep up with the flying speed of the fighter plane, the barrier itself will be torn apart by the continuous high-speed airflow.
Lin En suggested that they could consider coating the outer shell of the fighter with a layer of graphene. Once activated, it would form an electromagnetic shield around the fighter, which would be enough to effectively resist some low-level magic attacks. Most importantly, it would prevent the driver from suffering external mental damage - this is what the fighter pilots fear the most.
After thinking for a while, Lin En took a blueprint, wrote a chemical formula, and handed it to Dennis. "This is the method of making the Eternal Flame. You can try to use it in the development of offensive weapons for fighter planes, but... be careful!"
After being promoted to a legend, chlorine trifluoride is no longer his most important means of attack. So it is time to join the trend of industrial production. Only large-scale mass production can truly unleash its power!
Dennis took it very solemnly. He had heard about how terrifying this thing was. It could devour almost all known elements as nutrients.
Tim looked at the blueprint in Dennis's hand with great envy. The Eternal Flame was one of the few means that could allow great wizards like them to threaten legends.