"How is my research? Vice President Tim!" After Dennis was excited for a while, he turned to look at Tim who was stunned.
The latter was at a loss for words. Tim had no idea that Dennis's outrageous theory of explosive propulsion would actually come true. He could only say with a wry smile that he was indeed wrong. In the future, the institute would send more people to fully support his ideas. Research.
Seeing that Tim finally gave in, Dennis suddenly became angry.
During this year of researching explosive propulsion devices, he was often ridiculed by ignorant people, especially after the research reached a bottleneck, and the Magic Research Institute was not even willing to send more alchemists to assist him.
Firstly, there is a shortage of people everywhere in the kingdom. Secondly, many short-sighted great wizards think that his explosive advancement plan is too crazy and has no chance of success. It is just a waste of time and resources!
This is why Dennis had no choice but to recruit Lydia and others to assist him. Although these halflings do not know magic, they are very strong and have good engineering talents. They can always be used when doing some chores or assembling instruments. of use.
"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 with regret.
Otherwise, it would be appropriate to receive a Morning Star Medal for your own research!
"It's not too late. When you completely perfect the jet fighter, it will be just in time for next year's academic seminar." Lin En said with a smile, and then looked at the already red, vaguely melting, but still The flaming propeller warned.
"Master Dennis, I wonder if you have ever thought of changing the internal structure of the propeller to further increase the speed of the air jet..."
Now that Dennis has developed the prototype of the jet propulsion device, Linn 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 must know that what they are preparing to deal with this time is a cross-border war. The enemy cannot overestimate it. They must go all out and make as many preparations as possible.
A supersonic fighter jet is not much worse than a legend in terms of speed. If it can be equipped with a device that launches immortal flames or even small fusion bombs, it should be able to pose a considerable threat to the legend.
Still improving? The wizards present looked at Linn with strange eyes, and Tim was even more confused. In his opinion, seven hundred kilometers per hour was already a very terrifying speed, and one day was enough to travel within the empire. Visited several times.
Dennis was extremely excited. He had certainly considered changing the shape of the air chamber to increase speed. In fact, he had already done many 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 mixed explosion to the greatest extent, greatly reducing the possibility of explosion.
In order to let Lynn see more clearly, Dennis stepped forward directly, stopped the propeller, took it apart, and explained the internal structural design in turn.
Although every structural improvement is the result of dozens or hundreds of experiments, Dennis did not hide anything from this magic star. From the design concept to the problems that arise during practical application, he explained in great detail .
After all, Lin En was very generous and directly took out the drawings of the internal combustion engine and allowed him to conduct research on it. Dennis did not think that the other party would seize the results of the magic research.
After listening to what Dennis had to say, Linn pondered for a moment and then spoke quickly.
"Your design of the three-gas chamber structure is very good. The high-purity hydrogen and oxygen cannot be ignited alone to block the return flow of high-temperature gas generated by combustion, but this is not safe enough..."
"I suggest that you add a step of compressing the gas in the first half of the third gas chamber. This will not only increase the power provided when the gas is burned and erupted, but also create a pressure difference before and after, which will become a second insurance... …”
Lin En combined the design concepts of jet turbine engines and explained to Dennis how to compress the produced gas multiple times and send it into the combustion chamber through a plurality of rotating and fixed blades forming a V-shaped structure.
"But, wouldn't this propeller be more dangerous?" Tim couldn't help but interrupted. He felt that this magic star was coming up with some bad ideas.
The previous explosions of the thruster were due to the high-temperature airflow generated by the hydrogen-oxygen combustion reaction being too strong, which directly penetrated the gas chamber. If the density of the gas is increased again, although the thrust exploded during combustion will be stronger, there will be unexpected consequences. The likelihood is also higher.
"That's because the steel used to make it has poor pressure-bearing 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. He took the drawings on the table and continued to speak while drawing.
"Also, Master Dennis, the heat dissipation of your thruster is also a big problem. I suggest that the combustion chamber be designed as an inline structure, open a few vents, and directly use the high-speed airflow around the fighter plane to cool down. "
"Wonderful, what a wonderful idea..." Dennis said excitedly. Originally, he was going to fill the combustion chamber with cryogenic liquid to achieve the cooling effect, but Linn's design is obviously more energy-saving, because the wind comes directly from the fighter plane when it is flying. airflow.
Linn painted and added many ideas, so that the thruster that was modified seven times was like a stitch monster.
But as long as it’s useful and efficient!
Whatever is convenient for you!
"Why does this thruster structure look so strange?" Dennis glanced at Linn's improved drawings and asked in confusion.
It looks like two funnels at the front and back, and then the narrow part is spliced together.
"This is the structure that I have recently researched that is most in line with fluid mechanics. It is expected that doubling the flow rate of gas and liquid through the pipeline should not be a problem!" Lin En's lips curved up with a smile, and he explained that this structure In fact, it is the famous Laval tube, also known as the transonic nozzle.
Dennis frowned as he looked at the drawings. He believed that speed could be increased by optimizing the thruster pipe structure, but it would be too exaggerated to double the original speed by just changing one structure.
You know, his explosive thruster can originally reach a speed of 700 kilometers per hour, and after going through the step of compressing the gas, its speed will only be faster!
What is the concept of continuing to double on this basis?
Dennis really couldn't imagine it, let alone see what was so special about the trumpet-shaped structure in front of him that it could play such a big role.
"Would it work? You'll know just by giving it a try, right?" Linn said with a smile. He was also curious about what the suture thruster in front of him could do.
Dennis nodded, said nothing, rolled up his sleeves, and immediately started to improve the thruster.
Lin En was not idle either. He was personally responsible for making the third air chamber that needed to bear pressure, and even called Tim who was idle on the side.
The Grand Wizard possesses atomic-level control capabilities and can manipulate, analyze, and mimic almost all elements except special elements. When used in engineering, it can only be described as efficient.
Even with the addition of the inscription of the alchemy circle, the transformation of the new thruster was completed within two hours.
Next it’s time to experiment!
The alchemists and halflings like Darren immediately evacuated to a safe area. Perhaps because of his participation in the production, Tim didn't have such a big mental obstacle this time.
Dennis carefully pressed his hand on the magic transmission device, and with the rapid influx of magic power, the thruster was activated again.
A huge explosion soon sounded in everyone's ears, and then a red tail flame shot out from the nozzle behind the thruster.
The high platform used to fix the propeller below was constantly shaking. If Linn hadn't specially reinforced it, the propeller would have flown out at this moment!
"What a strong tail flame..." Dennis said in surprise. The high-temperature flames shot out from the nozzle were actually gathered into a jet flame column with a length of two meters, 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 the gaze of everyone, the scale on the thrust detection device is also rising...
Six hundred, seven hundred, eight hundred, nine hundred...and then it got stuck here without moving.
"Master Dennis, I'm afraid it has exceeded the limit of what we can detect!" an alchemist said in horror.
This means that the maximum speed of the jet stream exceeds one thousand kilometers per hour!
After more than ten seconds of acceleration, the shape of the high-temperature airflow shooting out of the nozzle changed again. Some of the flames near the nozzle were slightly sunk inward. The fireflow in this area was much brighter than the rest. In the shape of a ring, shaking slightly...
Lin En took the initiative to explain without waiting for anyone to ask. "This is the sonic ring, which means that the jet speed of the airflow exceeds the speed of sound propagation!"
The pressure of supersonic airflow is very high, so when it is injected into the air from the nozzle, it will expand rapidly, but the pressure of the expanded airflow 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. When the two meet and superimpose during the propagation process, they form rings on the propeller tail flame. It is the so-called sonic ring or Mach ring!
This colorful sonic ring looks particularly obvious because the steam flow formed by the mixed combustion of hydrogen and oxygen increases the humidity of the nearby air.
"The appearance of a ring means twice the speed of sound!" Lin En looked at the surging tail flames, but the second sonic ring did not appear. "It's a pity that it still hasn't reached twice the speed of sound, but I think it should be very close..."
According to his expectation, after the gas compression step, the high-temperature airflow burst out during combustion can 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. It's a pity that it was a little worse in the end.
"Speaker Lynn, you mean that the speed of high-temperature air jets now exceeds 2,000 kilometers per hour?" Tim said incredulously.
Although the speed of sound propagation will vary depending on air pressure and temperature, on average it is about 340 meters per second, which is 1,200 kilometers per hour!
And nearly twice the speed of sound means more than 2,000 kilometers per hour...
Tim clicked his tongue, what kind of monster were they trying to create?
Even Dennis was a little unbelievable. Even though he had guessed that after their modification, the power of the thruster would definitely improve qualitatively, he did not expect it to be this fast.
"Dean Lin En, can you fly so fast?" Lydia asked curiously.
"Not yet..." Linn shook his head. His flying speed was about 1.5 times the speed of sound.
"Doesn't that mean that as long as I drive this fighter plane, even the legendary wizard can't catch up with me?" Lydia said with great expectation.
"That's not certain." Linn laughed, thinking that Lydia was overconfident, so she poured cold water on her. "Some magics are very fast. For example, my electromagnetic rail gun can reach more than twenty times the speed of sound. If it were replaced by a laser beam, you might not even be able to dodge."
Lydia thought about the scene where she was flying a fighter plane and was pointed at by several laser beams, and immediately shrank her neck.
Linn asked Dennis to stop the operation of the propeller, disassemble it again to find out which point affected the speed of the airflow to reach the limit, and continued to improve the internal structure.
"You still want to change it?" The corners of Tim's mouth twitched involuntarily. Such a fast speed made him feel a trace of fear, which 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 breaking through the limitations of nature.
In his opinion, this speed is fast enough!
"It's only close to twice the speed of sound, and it's far from reaching the limit of jet propellers!" Linn said with a smile.
For jet fighters, three times the speed of sound is not much, five times the speed of sound is acceptable, and only ten times the speed of sound can make a qualified sentence...
"In addition, the shape of the fighter aircraft also needs to continue to be optimized. Supersonic speed and subsonic speed are two completely different concepts. Fighters flying at super high speed will accelerate the flow of surrounding air, compress the gas, and form a shock wave surface on the windward side of the aircraft... …”
Linn explained to Dennis the various obstacles that fighters would encounter when flying at high speeds, and drew the design drawings of a simple wind tunnel to simulate the airflow state during supersonic flight.
(End of chapter)
