KiloNewton/Pound foot of thrust into Horsepower units

[cjl]

With that car, it's not a case of road infrastructure. It's that 5000hp is likely not possible in a way that would be either pleasant to drive or remotely reliable. It's not that hard for a modern engine to make 5000hp for a few seconds on a dyno, but it's a very different thing to make it so you can drive it 10,000 miles without a complete engine rebuild.

 

[Arjun Singh]

I was procrastinating on a fuel cell technology based on non combustion hydrocarbon fuel to run electric cars. Seems futuristic but did find some studies on this topic. Anything on fuel cell tech except hydrogen fuel? No google links, just self articulated stuff.

 

[Arjun Singh]

With that car, it's not a case of road infrastructure. It's that 5000hp is likely not possible in a way that would be either pleasant to drive or remotely reliable. It's not that hard for a modern engine to make 5000hp for a few seconds on a dyno, but it's a very different thing to make it so you can drive it 10,000 miles without a complete engine rebuild.

On road (Not race course) top speeds may accommodate maximum speeding of 150-200 mph in bursts, that too on specially built speedways, if I am not being conservative. So a 5000hp engine would run let's say on 10-15% output power on average using the momentum of the vehicle. No matter how powerful an engine is, there must be some scientific RPM limit for on-road driving right? I wonder what speeds would a 5,000 HP engine would extract in full throttle?

 

[cjl]

It's really only constrained by money and reliability. Also, horsepower isn't just for top speed - it also impacts acceleration. Very few people ever reach the top speed of their vehicle, but many people do use 100% of its power.

 

[Arjun Singh]

https://www.boeing.com/features/2018/08/737max10-landing-gear-08-18.page
Boeing is introducing a new landing gear feature. Have seen another design with similar mechanism where the landing gear with two pairs of wheel extend horizontally with advanced landing and takeoff pattern.

 

[sophiecentaur]

jet engines just move air.

Are there any straight jet engines used these days? I thought they were more like Fan engines these days
- quieter and at least as efficient.

 

[Arjun Singh]

Are there any straight jet engines used these days? I thought they were more like Fan engines these days
- quieter and at least as efficient.

Elaborate.

 

[cjl]

Turbojet engines have 100% of the flow pass through the core of the engine, where it is heated (by burning fuel), just enough power is extracted to power the compressors, then it is passed through a nozzle to accelerate it out the rear of the engine. These are fairly low thrust and very inefficient until you get up to extremely high speeds, and I don't believe they're used at all any more even on things like jet fighters. Turbofans add additional turbines after the combustor to extract more energy from the core flow, and they use this to power a large front fan. This greatly increases thrust and efficiency at low speeds, at the cost of high speed performance. Since we aren't flying around at mach 2 all the time, this is a very worthwhile tradeoff. Even modern fighter jets use turbofans, but they use much smaller front fans with a much higher proportion still flowing through the core in order to keep the high speed performance acceptable.

 

[Arjun Singh]

Turbojet engines have 100% of the flow pass through the core of the engine, where it is heated (by burning fuel), just enough power is extracted to power the compressors, then it is passed through a nozzle to accelerate it out the rear of the engine. These are fairly low thrust and very inefficient until you get up to extremely high speeds, and I don't believe they're used at all any more even on things like jet fighters. Turbofans add additional turbines after the combustor to extract more energy from the core flow, and they use this to power a large front fan. This greatly increases thrust and efficiency at low speeds, at the cost of high speed performance. Since we aren't flying around at mach 2 all the time, this is a very worthwhile tradeoff. Even modern fighter jets use turbofans, but they use much smaller front fans with a much higher proportion still flowing through the core in order to keep the high speed performance acceptable.

You just differentiated high bypass and low bypass jet engines right? If I am not mistaken 4th generation fighters are all working on turbojets. Is turbofan the 5th generation upgrade? Also turbofans are bulkier than turbojets ain't they?

 

[russ_watters]

Are there any straight jet engines used these days? I thought they were more like Fan engines these days
- quieter and at least as efficient.

Probably, but either way I consider that semantics. A turbo fan "just moves air" even if some is bypassed around the jet part. Does that make it similar to a turboprop or turbo shaft on a helicopter? Perhaps. Yes, the line between types of engines and naming conventions can be blurry.

 

[cjl]

You just differentiated high bypass and low bypass jet engines right? If I am not mistaken 4th generation fighters are all working on turbojets. Is turbofan the 5th generation upgrade? Also turbofans are bulkier than turbojets ain't they?

All US 4th gen fighters (F14, 15, 16, and 18) run afterburning turbofans. It's true that they're bulkier than turbojets, but in jet fighters, they tend to run a pretty low bypass ratio which minimizes the extra bulk.

 

[sophiecentaur]

Probably, but either way I consider that semantics. A turbo fan "just moves air" even if some is bypassed around the jet part. Does that make it similar to a turboprop or turbo shaft on a helicopter? Perhaps. Yes, the line between types of engines and naming conventions can be blurry.

The Wiki article sort of confirms how I remembered it. There is a massive difference between (most if no all) jet engines and rockets. A lot of the the thrust that's delivered comes from a 'fan' which makes it very little different from a propellor. A gas turbine can drive another mechanism (copter rotor or alternator) but that isn't relevant to this thread (I think).
I interpreted your "just moves air" phrase in a way that you may not have intended. I think we agree largely,

 

[cosmik debris]

There's no real legal limit, other than that it becomes increasingly difficult to meet any kind of emissions standards and reliability. That having been said, I bet you're thinking of the (claimed) 5000 horsepower Devel Sixteen. I'll be surprised if it ever actually happens though...

Tyres would be expensive. I've heard of US$20000 for tyres of some of the Supercars.

Cheers

 

[Arjun Singh]

Tyres would be expensive. I've heard of US$20000 for tyres of some of the Supercars.

Cheers

Cool Helicopter.

 

[cjl]

Tyres would be expensive. I've heard of US$20000 for tyres of some of the Supercars.

Cheers

Yeah, though there's really no reason why tires should be anything close to that. Pretty much any of the supercars should work fine on something like Michelin Cup2 or Pilot Sport 4S tires, which (in supercar-ish sizes) tend to run around $400-600 per tire.

 

[Arjun Singh]

Yeah, though there's really no reason why tires should be anything close to that. Pretty much any of the supercars should work fine on something like Michelin Cup2 or Pilot Sport 4S tires, which (in supercar-ish sizes) tend to run around $400-600 per tire.

What makes a good tyre apart from the quality of rubber polymer used? I am a novice in this category and though this thread is for the discussion about aviation technology yet automobiles are quite similar.

 

[cjl]

There are a number of factors - the rubber compounds, the internal construction of the tire (materials used to reinforce both the sidewall and the tread area), the overall shape of the tire, the tread pattern that is cut into it, etc. There's also not one "best" design - it's heavily application specific.

 

[Arjun Singh]

There are a number of factors - the rubber compounds, the internal construction of the tire (materials used to reinforce both the sidewall and the tread area), the overall shape of the tire, the tread pattern that is cut into it, etc. There's also not one "best" design - it's heavily application specific.

So overall two primary components of tyre as a product. Material and Tread pattern, which as you say is specific to application. What I understand is, wet weather tyre would have different tread pattern from a hot weather tyre. Or a standard tarmac tyre would have different tread pattern from offroading type. Same between ones for high speed cars and regular cars. Also, vehicles with different center of gravity or weight or application will use tyres with different tread patterns. I am assuming that tyre material in all the mentioned categories can remain the same or with minor differences, right? And how do they differ in shape as all tyres are round and visible differ only in thickness?

 

[cosmik debris]

Yeah, though there's really no reason why tires should be anything close to that. Pretty much any of the supercars should work fine on something like Michelin Cup2 or Pilot Sport 4S tires, which (in supercar-ish sizes) tend to run around $400-600 per tire.

I agree, but in some countries, mine included, insurence and various certificates of fitness require the tyres to be speed rated at the top speed of the car regardless of whether you would actually drive that fast.

Cheers

 

[cjl]

I agree, but in some countries, mine included, insurence and various certificates of fitness require the tyres to be speed rated at the top speed of the car regardless of whether you would actually drive that fast.

Cheers

Both the Cup2 and the 4S have the highest speed rating in existence - (Y), which means in excess of 186mph.

 

[cjl]

So overall two primary components of tyre as a product. Material and Tread pattern, which as you say is specific to application. What I understand is, wet weather tyre would have different tread pattern from a hot weather tyre. Or a standard tarmac tyre would have different tread pattern from offroading type. Same between ones for high speed cars and regular cars. Also, vehicles with different center of gravity or weight or application will use tyres with different tread patterns. I am assuming that tyre material in all the mentioned categories can remain the same or with minor differences, right? And how do they differ in shape as all tyres are round and visible differ only in thickness?

Actually, among normal street tires, rubber compound is one of the most significant differences. There are differences in tread pattern as well, but the largest reason a snow tire works well on snow and ice, or why a high performance summer tire has much more grip on dry pavement, is because of the rubber compound used. A summer tire will have a soft compound designed to maintain its strength but be extremely sticky at high temperatures, while a winter tire will have a soft compound designed to stay pliable at low temperatures, and a tire designed for heavy loads or long endurance will have a harder compound more resistant to wear.

As for shape, I mean whether the tread is slightly rounded on the edges, or more squarish, whether the sidewalls slightly bulge, etc. The differences are subtle, but they are important when it comes to how a tire will perform.

 

[cosmik debris]

Both the Cup2 and the 4S have the highest speed rating in existence - (Y), which means in excess of 186mph.

Yes, but how much in excess? I don't think they mean 300mph.

Cheers

 

[cjl]

True, but there's no specific rating above 186, so from a legal perspective, there really isn't a way to distinguish the tires required for a Veyron from those required for a Corvette. If you wanted to spend any significant amount of time over 200mph, you'd probably just want to contact the tire manufacturer in those cases, since there isn't actually a rating for it.

 

[Arjun Singh]

True, but there's no specific rating above 186, so from a legal perspective, there really isn't a way to distinguish the tires required for a Veyron from those required for a Corvette. If you wanted to spend any significant amount of time over 200mph, you'd probably just want to contact the tire manufacturer in those cases, since there isn't actually a rating for it.

What about tyre refurbishing? How effective is it to recycle an old tyre and make it workable again? There is already a good market for refurbished high end tyres sold in cheaper second hand markets.

 

[cjl]

I have never heard of refurbishing tires for high performance sports car use, and even for cheaper cars, I believe it's very rare. It's very common in the US for heavy commercial use on trucks and buses though.

 

[Arjun Singh]

I have never heard of refurbishing tires for high performance sports car use, and even for cheaper cars, I believe it's very rare. It's very common in the US for heavy commercial use on trucks and buses though.

Not that rare to say. Perhaps not a common trade yet it exists moderately available. See, these layers to product trade increases aspirational value for the expensive products. Someone using a refurbished high end tyre is more likely to buy it new someday as compared to someone who regularly buys moderately expensive tyre and is not aware of the performance upgrade such a tyre can give to his or her vehicle. Just a thought! Works well for many value intensive product categories.

 

[Arjun Singh]

Cool Helicopter.

Hey any comments about this new copter? Considering that coastal cities, with over water air space can accommodate a good number of air taxis and privately owned copters. Does anyone thinks that role of turboshaft engine makers in that scenario would become more prolific in terms of price, transmission innovation, variable fuel compatibility, design and overall performance? Also, would that make the modern copters become completely safe as a common form of inland urban transportation? Want to understand community's views.

 

[Arjun Singh]

Are there any straight jet engines used these days? I thought they were more like Fan engines these days
- quieter and at least as efficient.

Do you mean Turbojets getting replaced by Turbofans? There has been some comments about this in the thread. As I have understood, apparently due to their enhanced fuel efficiency turbofans or high bypass jet engines are slowly getting preference over turbojets. Still due to the size and power plant design they have very specific applications. Keep contributing. Cheers!

 

[Arjun Singh]

Among road legal sports cars this one has a lot HP:

https://de.wikipedia.org/wiki/Bugatti_Chiron

I don't know about other types of vehicles though.

What about wheeled construction machines?

 

[Arjun Singh]

Probably, but either way I consider that semantics. A turbo fan "just moves air" even if some is bypassed around the jet part. Does that make it similar to a turboprop or turbo shaft on a helicopter? Perhaps. Yes, the line between types of engines and naming conventions can be blurry.

Can a similar design be made applicable to high speed ships? I believe majority naval fleets (commercial or defence) currently run on diesel or SHS piston engines driving a propeller. Viscosity and fluid mechanics may differ from air yet the propulsion theory is the same. What do you think?

 

[A.T.]

What about wheeled construction machines?

What about googling it yourself?

 

[Arjun Singh]

I assume you're talking about the power or thrust maximum ratings. Since the engine supplier doesn't know which propeller is going to be used, or other relevant variables, it's simpler in the case of propeller-driven aircraft to specify maximum rated power. The designer multiplies power by estimated propulsive efficiency to arrive at thrust available.

In addition to the max ratings there is also thrust and power output under operating conditions, which varies with throttle setting, airspeed, and other factors. Aircraft engine horsepower is not directly comparable with automobile engines. Cars use a different measurement protocol.

True with jet engines. Piston engines and direct drive electric motors are often designed to provide lots of torque at low speed. A slow-turning propeller can produce thrust more efficiently.

Confusingly, engineers often say mass when they mean weight. If a body is said to "weigh" 10 kg, it is understood colloquially to mean the amount of gravitational force the body would experience near the Earth's surface.

In particle physics, when two sub atomic particles interact, is gravity involved in it given their quantum weight which I am sure has a specific value? Also do their post interaction trajectories affected by gravity? Let's assume that the electromagnetic force of the respective atom is balanced in the interaction.

 

[Arjun Singh]

What about googling it yourself?

Thanks for your advice. Idea is to know the opinion on topics to share understandings. Contributory extent of members here is based on free will.

 

[David Lewis]

…when two sub-atomic particles interact, is gravity involved in it given their quantum weight which I am sure has a specific value? Also do their post-interaction trajectories affected by gravity? Let's assume that the electromagnetic force of the respective atom is balanced in the interaction.

Unless it's massless, each quantum object does have its own gravitational field but it is too weak in most cases to have any significant effect by itself. You are dealing with strong and electro-weak interactions when it comes to protons, neutrons, quarks, hadrons, etc.

 

[Arjun Singh]

Unless it's massless, each quantum object does have its own gravitational field but it is too weak in most cases to have any significant effect by itself. You are dealing with strong and electro-weak interactions when it comes to protons, neutrons, quarks, hadrons, etc.

Didn't understand the strong and electro-weak interactions. Do you mean the chemical or ionic reactivity involved in their interaction or is it something to do with their valance relativity? I mean their atomic number relativity or position in the atom? I am not a trained physicist so pardon the crude terminology.

 

[David Lewis]

The four fundamental forces are:

Strong interaction, or strong nuclear force (nuclear fusion)
Weak interaction (nuclear fission)
Gravity
Electromagnetism (chemistry)

I've put in parentheses the corresponding phenomena to which the four forces informally relate.

 

[Arjun Singh]

The four fundamental forces are:

Strong interaction, or strong nuclear force (nuclear fusion)
Weak interaction (nuclear fission)
Gravity
Electromagnetism (chemistry)

I've put in parentheses the corresponding phenomena to which the four forces informally relate.

To conclude, any sub atomic or molecular interaction is a product of all these forces working as per their quantum relativity to the interactive premises of the reaction. Depending upon the nature of the reaction the designated force leads the process. Is this a closest to correct statement?

 

[David Lewis]

Of course. As you pointed out, depending on the branch of science, you may be focusing on one interaction at a time though. In everyday chemical reactions you will not be concerned about strong or weak nuclear forces directly as you would be in designing an atomic reactor. And in celestial mechanics, you will primarily deal with gravitation, and so on.

 

[Arjun Singh]

Of course. As you pointed out, depending on the branch of science, you may be focusing on one interaction at a time though. In everyday chemical reactions you will not be concerned about strong or weak nuclear forces directly as you would be in designing an atomic reactor. And in celestial mechanics, you will primarily deal with gravitation, and so on.

Broadening the context, I have been conceptualizing a clean plastic to fuel process through plasma conversion. If I am not mistaken, at absolute plasma state all materials become identical and can be utilized for mechanical work without any harmful fallout. My question is, once the plasma precipitates can the material be recovered back to some reusable polymer state minus the used mass as heat loss and is it possible for the entire material to be utilized without any residue?

 

[jbriggs444]

Broadening the context, I have been conceptualizing a clean plastic to fuel process through plasma conversion. If I am not mistaken, at absolute plasma state all materials become identical and can be utilized for mechanical work without any harmful fallout. My question is, once the plasma precipitates can the material be recovered back to some reusable polymer state minus the used mass as heat loss and is it possible for the entire material to be utilized without any residue?

This appears to be word salad. Possibly you envision heating up a material to the point where its atomic nuclei and their component protons and neutrons spontaneously disassociate into a "plasma" of quarks. We cannot heat a meaningful quantity of material to such a temperature, cannot confine the resulting plasma, cannot use such a process to perform useful work and cannot cause any particular material to "precipitate out". The idea of the residue being reusable is not sensible since the energy inputs to the process would be huge and almost certainly unrecoverable.

 

[Arjun Singh]

This appears to be word salad. Possibly you envision heating up a material to the point where its atomic nuclei and their component protons and neutrons spontaneously disassociate into a "plasma" of quarks. We cannot heat a meaningful quantity of material to such a temperature, cannot confine the resulting plasma, cannot use such a process to perform useful work and cannot cause any particular material to "precipitate out". The idea of the residue being reusable is not sensible since the energy inputs to the process would be huge and almost certainly unrecoverable.

Perhaps.

 

[Arjun Singh]

What are group's comment on Bell Boeing V-22 Osprey? I feel the aircraft design is quite sufficient to inspire a class of heli-crafts of near future for both passenger and cargo modes. Yet it is not much talked about.

 

[jbriggs444]

What are group's comment on Bell Boeing V-22 Osprey? I feel the aircraft design is quite sufficient to inspire a class of heli-crafts of near future for both passenger and cargo modes. Yet it is not much talked about.

What market would it be serving? If you are competing against turboprop craft, the ATR 72 is larger, cheaper, faster and has fewer crew.

 

[Arjun Singh]

What market would it be serving? If you are competing against turboprop craft, the ATR 72 is larger, cheaper, faster and has fewer crew.

ATR 72 is a conventional fixed wing aircraft. I am talking about hybrid design of the Osprey. Aviation infrastructure, especially in emerging economies is concentrated towards major cities. Short Take-off/Vertical Take-off and landing aircrafts on the other hand do not require huge runways and thus can be served by airports with limited space and thus comparatively affordable infrastructure. Aircrafts like Osprey are basically made for defence purposes and here the operating costs are superseded by their unique field deployment capacities. A class of aircrafts built on such a platform for civilian use with comparative long haul and passenger capacities to their fixed wing counterparts, would surely consider low operating and maintenance costs as its prime design feature. Depending upon their application, these aircrafts can add an entirely new branch of premium and civil utility aviation infrastructure, to operate coordinatively alongside the present day high yield conventional infrastructure.

 

[cosmik debris]

Unless it's massless, each quantum object does have its own gravitational field

Massless particles have a gravitational field too.

Cheers

 

[Arjun Singh]

Massless particles have a gravitational field too.

Cheers

Ain't these particles somehow part of gravity itself?

 

[cosmik debris]

Ain't these particles somehow part of gravity itself?

Ummm, no!

Cheers

 

[Arjun Singh]

Ummm, no!

Cheers

So how would you describe their quantum presence? Is their masslessness designates some sort of quantum threshold for energy to create mass?
What's your view?

Cheers!

 

[cosmik debris]

So how would you describe their quantum presence? Is their masslessness designates some sort of quantum threshold for energy to create mass?
What's your view?

Cheers!

I don't know what any of this means, sorry.

Cheers

 

[David Lewis]

What are group's comment on Bell Boeing V-22 Osprey?

If you need an airplane with VTOL capability then the Osprey might be one to consider, but you will pay dearly for that capability.

Ain't these particles somehow part of gravity itself?

My understanding is a photon will warp spacetime because of its momentum.