It is not a day or two for the automobile industry to learn from the experience of the aviation industry, and the turbochargers that are quite common in cars today are learned from airplanes.

The thin air at high altitude makes the engine unable to obtain sufficient oxygen, which limits the aircraft to obtain the advantage of high altitude and high speed, so the engineers invented the exhaust gas turbocharger, which uses the exhaust gas waste discharged by the engine to drive the turbocharger to make more air enter the engine inlet tract, so as to increase oxygen and efficiency, and increase the output power of the engine.

This trick was first learned by the car designers, and turbocharging allowed formula cars with limited displacement to exert more power, which in turn improved performance. As oil prices become more and more expensive, designers of ordinary civilian vehicles have also begun to use this trick, which can not only increase engine output and improve acceleration performance, but also promote combustion and reduce pollutant emissions, which is quite a cost-effective design.

Of course, turbocharging is not without disadvantages, first of all, the high-temperature exhaust gas in the supercharger goes through, in addition to being recovered part of the kinetic energy, there is also a part of the waste heat is also "recovered", resulting in an increase in the supercharger and intake temperature, the former brings some safety hazards, the latter reduces the efficiency of the engine, and needs to add an intake cooler, bringing more costs. Therefore, only small displacement cars with weak power are usually equipped with turbocharging as standard, and large displacement cars such as sports cars are naturally aspirated.

As airplanes entered the jet age, there were also attempts to bring gas turbines to the ground.

Jet engines have been around for more than 80 years, and the largest family of them is gas turbines, which are available in a variety of different applications. Among them, the turbojet high-speed performance is good, mainly in use by fighters, the turbofan strengthens the low-speed performance, large civil aviation and most of the fighters use it, the turboprop speed is slower and more cost-effective, and it is deeply loved by regional airliners and transport aircraft, the propeller fan combines the advantages of the turboprop and the turbofan, which is theoretically the strongest, but first, a special high-speed propeller is needed, and the second is that the propeller appears to be very, resulting in only the former Soviet Union's An-70 transport aircraft in the world using it, and the two-layer CV-27 on the latter's wings is very conspicuous and very recognizable to the rotary propeller fan.

If you replace the propeller of the turboprop engine with something else, it becomes a turboshaft engine, which can be used to drive the rotor of a helicopter, or to generate electricity.

The kind of "rocket cars" that challenge the rapid speed on the ground use turbojet engines, and their slender bodies always drag long flaming tails when speeding at high speeds, which is very eye-catching.

It's just that the speed is too fast, this kind of car that can exceed a thousand kilometers per hour is not practical, and can only be used in a special test site, or on an endless flat sand for a short time.

In the 60s and 70s, both the United States and the Soviet Union experimented with jet propulsion locomotives, and the M-497 of the Central Railroad Company and the SVL of the Soviet Union were the wonders of two turbojets overhead. It's a pity that the cornering performance of this locomotive is too bad, and in the end there is no follow-up.

However, the use of turboshaft engines on trains is quite successful, and Bombardier of Canada has developed an electric drive gas turbine locomotive in this century, using the PW150 series turboshaft engine of Pratt & Whitney, one of the three giants of aviation development, as the power core, and the turboshaft drives the generator and then the electric motor drives the wheel forward.

It's just that later, when competing with electric EMUs for the share of high-speed rail, it still lost, and there was no follow-up.

After all, the places that need high-speed buses are often economically developed and densely populated areas, which are generally suitable for electric locomotives due to gentle terrain and sufficient power supply, and will also have the opportunity to upgrade to maglev trains in the future, while gas turbine locomotives that need to generate their own electricity are not very pleasing because of the problems of emissions and noise.

And there is a problem with the turboshaft, it rotates too fast, and it has to slow down when used in helicopters and trains.

The rotors of a helicopter are rotating wings, which are similar in cross-section to the wings of a fixed-wing aircraft, and can also cause a difference in the velocity of the air flowing through the upper and lower wings, which in turn generates lift according to Bernoulli's principle, which is different from a propeller that pushes the air violently in one direction.

As a rotating object, the rotor has the same angular velocity in all parts except the axis, but the linear velocity at different positions is very different, and the farther away from the axis of rotation, the higher the linear velocity.

A typical example of this is the legendary "first supersonic object made by man" - the long whip, which an experienced person can shake to make a very loud "pop" sound, that is, the linear speed of the whip briefly exceeds the speed of sound, causing a sonic boom caused by a shock wave.

When the aircraft crosses the speed of sound in the air, it will also produce a strong sonic boom, and the vibration generated at the same time is a considerable load on the fuselage. Later supersonic aircraft had pointed noses and triangular wings swept backwards, just to break the sound barrier more safely and achieve supersonic speed.

With the structure of a helicopter, supersonic speed is not an unbearable target, so the designer must control the linear speed of the rotor wing to be slightly below Mach 0.9 to avoid "hitting" the sound barrier, which will bring sonic boom noise at least and destroy the wing at worst.

This leads to the rotor can not be very long, let alone can not rotate very fast, can only increase the number of rotor blades to increase the lift and speed, usually the rotor rotation speed is only a few hundred revolutions per minute, while the speed of the turboshaft engine is as high as tens of thousands of revolutions per minute, so the turboshaft helicopter also has to install a complex reducer to reduce the speed.

Turboshafts used in power generation on trains and ships also have this problem.

Because the induced electromotive force is the relationship of alternating, the electricity generated by the generator is alternating current, the so-called DC generator is offset by the commutator and brush, in order to output direct current, but because of the complex structure and the application remains unchanged, the modern power system still generally uses alternating current, and only when it is needed, it becomes direct current through the AC/DC converter. However, with the popularity of smartphones, the demand for 5V DC used in them has increased greatly, resulting in the emergence of power strips and automobiles with their own 5V DC output.

The frequency of alternating current is determined by the number of rotations of the generator's magnetic poles, but after a hundred years of development, the frequency of civil electrical equipment has been standardized to 50 (ohm) / 60 (US) hertz, which in turn limits the speed of the generator, that is, a maximum of 3600 revolutions per minute, otherwise the electricity sent out will be used.

Therefore, for fly-by-wire ships and fly-by-wire trains, reducer vs high-frequency motor is a pair of tangled problems, if you want to facilitate the use of existing generators and electrical appliances, you must use the reducer to reduce the output speed of the gas turbine, otherwise you have to develop special high-frequency generators and motors.

Fortunately, with the development of the times, some military high-frequency motor technology has gradually spread to the civilian population, micro gas turbine generators (MTG) usually have built-in high-frequency generators, and the output of high-frequency alternating current is rectified into high-voltage direct current, and then becomes civilian 50\/60 Hz alternating current.

The WR50 generator on the Dark Horse also uses a similar design in order to achieve a smaller and lighter form factor.

In fact, in general, the performance of the WR50 with a power generation of only 50 kilowatts can only be said to be average, and the on-board MTG has long had hundreds of kilowatts of products on sale.

The reason why it is so weak is mainly because it is independently developed by Pony's North American R&D center, which is essentially a practice work for technical verification.

On the one hand, although the technology of the turboshaft has spread, the top technology has always been in the hands of several major aviation companies, and they do not look at the power generation market, especially the micro power generation market such as MTG, so Pony North America can only obtain technology by recruiting graduates of related majors, acquiring other third-rate small companies and even private team technology, the technical foundation is still relatively weak, and the standard is set too high will definitely lead to a further surge in R & D costs.

On the other hand, they also have to take care of the problem of technology blockade. The United States is relatively open to the sale of civilian products and technologies, but if it is exported to the other side of the Pacific Ocean, it is another matter, if it is hard to develop a bomb-blown MTG, maybe a federal investigator in a black suit will come to the door, take out his ID and say, "We have reason to suspect that you are stealing restricted technology, please come with us", then it is a cup.

Under many factors, the pony's first micro-combustion can only be so decent, the only highlight is that the volume and weight control are relatively good, and the electronic control system is quite advanced. Pony is essentially an electronics company, and the vehicle balance system developed is actually in the same vein as the flight control system on the drone. Their method of building a car is to directly enlarge the quadcopter, stuff it into the car shell, and then install the wheels, which is why they always like true four-wheel drive when building cars, and it is more troublesome to reduce it to two-wheel drive or traditional central shaft transmission.

Fortunately, for the "dark horse", a 50 kilowatt generator is almost enough. This power is not always better, because more power output means more and hotter exhaust emissions, which must put forward higher requirements for the cooling system, and thus squeeze the limited space on the car.

The reason why it is almost enough is because the real power supply of this car is a set of supercapacitors, MTG actually converts fuel into electrical energy to charge it, and then the capacitor bank drives the electric motor and other electrical equipment on the car. The four electric motors can burst out with a maximum power output of 400 kilowatts, which means that the maximum power exceeds 500 horsepower, which is just the standard of a supercar, and of course there is still some distance from the Bugatti with more than 1000 horsepower.

However, because of the characteristics of low speed and high torque of the electric motor, the explosive power of this car is quite good, and the ability to accelerate sharply is outstanding. In particular, the lighter weight makes this car faster than electric cars in the same class, and the acceleration time of 100 kilometers in the test is less than 4 seconds, and the top speed can exceed 350kmph.

It's a pity that this speed doesn't last long, the supercapacitor is characterized by high current and high power, which is convenient for burst speed, but its power density is not much different from that of lithium-ion battery packs, and it will still drag down the weight of the vehicle with an oversized capacitor pack, so it will only take a few minutes to run out of power if you drive at full speed.

Fortunately, there is also a micro-combustion system that continues to generate electricity, and there is no need to worry about turning off the engine in a few minutes, but you need to run at a low speed for a while to recharge, so this "dark horse" is also a sports car with a skill CD (cooldown), so you can enjoy the thrill of galloping, and you must wait patiently for the car to be ready.

Not only do you have to wait for the capacitor bank to be fully charged, but you also have to wait for the micro-combustion system to cool down, so this "cooling time" is also very worthy of the name. When the vehicle is driving at high speeds, the generator will also run at full power, which generates a considerable amount of heat, and it also takes a certain amount of time to fully dissipate it.

Fortunately, this is a coupe, and the micro-combustion system is designed behind the cockpit, similar to the position of the mid-engine of a supercar, and is designed with special cooling air ducts, which can use the oncoming airflow of the vehicle to cool the micro-combustion when driving at high speeds. In fact, it is difficult to drive at an ultra-high speed of more than 200 kilometers per hour on most roads, and the power will naturally be less when the speed is slow, and the heat will be reduced, but there is no need to worry about heating yourself to death.

On low-speed roads, powerful powertrains are not useless, they allow the car to burst into powerful acceleration when needed, UU reading books (and the four-wheel independent power also makes the car very maneuverable, very agile to drive.

At the auto show, in addition to showing the prototype car, Bee also prepared a demonstration video of the cool bunker to show the extraordinary performance of the car, and this video is a first-person VR cockpit video provided by Atletico Madrid, which is full of presence.

As a result, there was a magical scene in front of the bee booth: many people wearing a square cardboard box made of brown cardboard were looking back and forth, their faces full of surprise.

Last year, at the I/O conference, a gadget called "Made of Cardboard" made of a simple pair of VR glasses, then tucked into the phone and put on the head, with the help of the corresponding mobile phone app to play VR videos.

Limited to the resolution and brightness of the mobile phone screen, the picture quality is of course not as good as the professional equipment of Dream Walker, the only advantage is that it is cheap, it can allow people to contact VR at a low cost, its main material is cardboard, and the auxiliary material is convex lens, magnets, Velcro, which add up to only a few dollars in cost.

Of course, bees can use Dreamwalker 5 to bring a better viewing experience to the audience, but for the sake of topicality, they finally chose the scheme of distributing cartons for free, anyway, the high-definition version has also been transmitted to the Internet, and those who are interested can take it for themselves. For mobile phone users, please visit http://m.piaotian.net