"How's my research going? Vice Dean Tim! Dennis was excited for a while, then turned to look at Tim, who was stunned.

The latter was speechless for a while, and Tim didn't expect Dennis's outrageous explosion propulsion theory to really be done, so he had to smile bitterly and say that he was indeed wrong, and the research institute would send more people to fully support his research in the future.

Seeing that Tim finally relented, Dennis suddenly let out a bad breath.

In the year he had been researching explosive propulsion devices, he had been ridiculed by the ignorant, especially since the Institute of Magic was reluctant to send more alchemists to assist him after his research had reached a bottleneck.

The first is that there is a shortage of people everywhere in the kingdom now, and the second is that many short-sighted great wizards think that his explosion advancement plan is too crazy and has no chance of success at all, just a waste of time and resources!

This is also the reason why Dennis has no choice but to bring in Lydia and others to help him, although these halflings do not know magic, but they have great strength and good engineering talents, and they can always come in handy when doing some chores or assembling instruments.

"It's a pity that it's a little late, but it would have been perfect if it had been completed in time for this year's symposium!" Dennis said regretfully.

Otherwise, it would be appropriate to receive a Morning Star medal for your research!

"It's not too late, when you have completely perfected the jet fighter, just in time for next year's academic seminar." Lynn said with a smile, and then looked at the thruster that was already red and faintly showing signs of melting, but was still bubbling with fire, and reminded.

"Master Dennis, I don't know if you ever thought about changing the internal structure of the thruster to further increase the speed of the air jet......

Now that Dennis has come up with the prototype of a jet propulsion device, Lynn is naturally no longer hiding it.

How can a jet plane reach a speed of 700 kilometers per hour enough?

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, and the enemy cannot overestimate it, and they must go all out and make as many preparations as possible.

A supersonic fighter is not much worse than a legend in terms of speed, and if it can be equipped with a device that launches indestructible flames or even small fusion bombs, it should be able to pose a big threat to the legend.

Also raised? The wizards present looked at Lynn with a strange gaze, and Tim was even more stunned, in his opinion, 700 kilometers per hour was already a terrifying speed, and a day was enough time to travel back and forth within the empire several times.

Dennis was extremely excited, of course he had considered this by changing the shape of the gas chamber to speed up, in fact, he had already done a lot of experiments.

For example, the third gas chamber of the thruster has been improved by him, which can spray out the high-temperature and high-speed air flow brought by the hydrogen-oxygen mixed explosion to the greatest extent, which greatly reduces the possibility of explosion.

In order to make Lynn see more clearly, Dennis stepped forward, stopped and disassembled the thruster, and explained the internal structural design in turn.

Although each structural improvement is the result of dozens or hundreds of experiments, in front of this magic star, Dennis has no intention of concealing it, from the design concept to the problems that arise in practical application, it is very detailed.

After all, Lynn was very generous and directly took out the drawings of the internal combustion engine, and by the way, let himself conduct research, and Dennis didn't think that the other party would do anything to snatch the results of the magic research.

After listening to Dennis's story, Lynn pondered for a moment, and then quickly spoke.

"It's a good idea to design a three-chamber structure that blocks the return of high-temperature gases from combustion through the fact that highly pure hydrogen and oxygen cannot be ignited alone, but that's not enough to ......"

"I suggest that you add a compressed gas step in the first half of the third gas chamber, which can not only increase the power provided by the gas combustion eruption again, but also create a pressure difference between the front and back, which becomes a second safety ......."

Combined with the design concept of a jet turbine engine, Lynn explained to Dennis how to compress the gas produced multiple times and feed it into the combustion chamber through multiple rotating and fixed blades that form a V-shaped structure.

"But, isn't this thruster more dangerous?" Tim couldn't help but interrupt, thinking that the magic star was just coming up with some bad idea.

If the density of the gas is increased again, the thrust that erupts during combustion is stronger, but the possibility of accidents is also higher.

"That's because the steel that makes it has so poor pressure and heat capacity that this level of pressure is nothing if you replace it with a stronger alloy or mythril in key parts." Lynn shook her head, took the drawing on the table, and continued to speak as she started drawing.

"Also, Master Dennis, the heat dissipation of your thrusters is also a big problem, I suggest that the combustion chamber can be designed as an embedded structure, open a few vents, and directly use the high-speed airflow around the fighter plane to cool down."

"Wonderful, what a brilliant idea...... Dennis said excitedly, originally he was going to fill the combustion chamber with cryogenic liquid to achieve the cooling effect, but Lynn's design was obviously more energy-efficient, because the wind came directly from the air flow of the fighter plane.

Lynn scribbled and added a lot of ideas to it, so that the thruster that came out of seven changes and eight changes was like a stitching monster.

But as long as it's useful and efficient!

How convenient and how to come!

"Why does this thruster structure look so strange?" Dennis glanced at Lynn's improved drawings and asked, puzzled.

It looked like two funnels, the front and back, and then the narrow spots were stitched together.

"This is the most hydrodynamic structure I've recently studied, and I don't expect it to be a problem to double the flow rate of gases and liquids through the pipes!" The corners of Lynn's mouth hooked up a smile, and he explained that this structure is actually the famous Laval tube, also known as the transonic nozzle.

Dennis couldn't help frowning as he looked at the drawings, he believed that he could increase the speed by optimizing the thruster pipe structure, but it was a bit too exaggerated to change the structure to double the original speed.

You know, his explosive thruster was originally able to reach a speed of 700 kilometers per hour, and after the step of compressed gas, its speed will only be faster!

What kind of concept is it that can continue to double on this basis?

Dennis really couldn't imagine, let alone see what was so special about the trumpet-like structure in front of him, and it could play such a big role.

"Okay, just give it a try, won't you?" Lynn said with a smile, and he was also curious about how far the suture thruster in front of him could go.

Dennis nodded, didn't talk nonsense, rolled up his sleeves, and started to work on the thruster improvements.

Lynn was not idle, personally responsible for making the third gas chamber that needed to be under pressure, and even called Tim, who was idle on the side.

The Great Wizard has atomic-level control capabilities, which can manipulate, analyze, and mimic almost all elements except for special elements, which can only be described as efficient in engineering.

Even with the burning of the alchemy circle, the transformation of the new thruster was completed in less than two hours.

Now it's time to experiment!

The alchemists and Darren and the halflings immediately evacuated to safety, perhaps because of their participation in the production, Tim did not have such a big mental obstacle this time.

Dennis cautiously pressed his hand on the mana teleporter, and the thruster was activated again as the mana poured in.

A loud pop soon rang in everyone's ears, followed by a crimson tail flame bursting out of the nozzle behind the thruster.

The high platform below that is used to hold the thrusters is constantly shaking, and if it weren't for Lynn's special reinforcement, the thrusters would have flown out in an instant!

"What a strong tail flame...... Dennis said in amazement, and the high-temperature flames that burst out of the nozzle were gathered into a two-meter-long jet of fire, even longer than the thruster itself!

Even with the naked eye, he could see that the thrust provided by this thing was several notches 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 and didn't move.

"Master Dennis, I'm afraid it's beyond the limits of what we can detect!" An alchemist said in horror.

This means that the maximum speed of the jet stream exceeds a thousand kilometers per hour!

After more than ten seconds of acceleration, the shape of the hot air jet that burst out of the nozzle changed again, and some of the flames near the vent were slightly concave inward, and the fire in this area was much brighter than the rest of the place, forming a circular shape and shaking slightly......

Lynn didn't wait for everyone to ask, and took the initiative to explain. "This is the ring of sound, which means that the jet speed of the air stream exceeds the speed of sound travel!"

The supersonic airflow pressure is very high, so when it is injected into the air from the nozzle, it expands rapidly, but the pressure of the expanded airflow is significantly lower than the atmospheric pressure, so it is compressed again.

In this way, the supersonic air flow will reciprocate between expansion and compression, and this process will form expansion waves and compression waves, which meet and superimpose in the propagation process, forming a ring on the tail flame of the thruster, which is the so-called sonic ring or Mach ring!

This colourful ring of sound looks particularly noticeable because the steam flow created by the mixed combustion of hydrogen and oxygen raises the humidity of the nearby air.

"The appearance of a ring represents double the speed of sound!" Lynn looked at the surging tail flames, and the second ring of sound didn't come out. "It's a pity that we still can't reach twice the speed of sound, but I think it's pretty close......"

According to his expectations, after the gas compression step, the high-temperature air flow that bursts out during combustion can reach subsonic speed before entering the Laval tube, and it should be able to reach about twice the speed of sound after two acceleration before and after passing through the Laval tube, but unfortunately it is still a little worse in the end.

"Speaker Lynn, do you mean that the current jet of hot air is now jetting faster than two thousand kilometers per hour?" Tim said incredulously.

Although the speed of sound propagation varies according to the difference in air pressure and temperature, it is about 340 meters per second on average, which is 1,200 kilometers per hour!

Nearly twice the speed of sound means more than 2,000 kilometers per hour......

Tim smacked, what kind of monster are they trying to build?

Even Dennis was a little incredulous, even if he had guessed that after their transformation, the power of the thruster would inevitably be qualitatively improved, but he didn't expect it to be so fast.

"Dean Lynn, can you fly that fast?" Lydia asked curiously.

"Not yet," Lynn shook his head, his flight speed was about one and a half times the speed ......of sound.

"Doesn't that mean that as long as I fly this fighter, even the legendary wizard can't catch up with me?" Lydia said expectantly.

"It could be." Lynn laughed, and Lydia poured cold water on her overconfidence. "The speed of some magic is still very fast, such as my electromagnetic railgun, which can reach more than twenty times the speed of sound, if you change to a laser beam, I am afraid that you will not even have the possibility of dodging."

Lydia thought about the scene of herself piloting the fighter plane and being pointed at by several laser beams, and suddenly shrunk her neck.

Lynn told Dennis to stop the thrusters, re-dismantling them to find out what was affecting the speed of the airflow to the limit, and continued to improve the internal structure.

"Still want to change?" The corners of Tim's mouth twitched, and the speed of this 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 could only be achieved by legends, which meant breaking the sound barrier and breaking through the limits of nature.

In his opinion, such a speed is fast enough!

"It's just close to twice the speed of sound, and it's nowhere near the limit of jet thrust!" Lynn said with a smile.

For jet fighters, triple the speed of sound is not much, five times the speed of sound is acceptable, and ten times the speed of sound is enough to say the last sentence......

"In addition, the shape of the fighter also needs to continue to be optimized, supersonic speed and the speed of sound below two completely different concepts, ultra-high-speed flight fighters will drive the surrounding air to accelerate the flow, compress the gas, and form a shock surface at the windward part of the aircraft......"

Lynn explained to Dennis the various obstacles that the fighter would encounter when flying at high speeds, and drew the design drawings of the simple wind tunnel to simulate the air flow state during supersonic flight.

(End of chapter)