A common enabler for all alternative fuels

[2inquisitive]

Harmonic_Subset,

A Superbus solves all these problems: a door for each seat, and a seat for each passenger. There is no question about how many passengers can squeeze in, because the bus is full when the seats are full. Each passenger swipes his re-loadable debit card, their doors close, and the bus moves on to the next stop.

The 'Superbus' seems very impractical to me. You say 'a door for each seat'. The article states the bus is a wide as a regular bus. Are there only two seats across, one for each door on each side? There would be a lot of wasted space in the middle of the bus, if that is the case. If it seats four of five across, how do the passengers sitting in middle get out when they can't stand up straight? Many older people and fat people are not agile enough to climb over others sitting between them and the door. If one passenger exits through a door at a stop, how does the driver know if someone else gets on the bus through the open door, and if not, how does he get the door closed? With doors on both sides of the bus, wouldn't it be necessary for the bus to be completely separated from any other traffic on both sides at all stops?
All those doors add a lot of weight to the bus and are expensive to build. The service life of the bus is estimated to be less than 1/4 that of a regular bus, so four of the 'superbusses' would have to be purchased for each one of the regular busses, even if each had the same total capacity. At best, those superbusses would fill a 'niche' role.

You seem to be a young person with no family and no home to provide for. The type of vehicle suitable for you can be very impractical for families with kids to transport, home supplies from lawnmowers to microwaves to transport, and large amounts of groceries and soft drinks to bring home from the supermarket. I agree that large SUVs are dinosaurs for most people now-a-days, but larger vehicles that have adaquate seating for the whole family and storage space for bulky items are a necessity for many people. An unmarried collage student driving a large SUV is silly, but a rugged SUV with a long service life is a little more practical for a farmer with 6 kids.

 

[leopold]

Your absurd response requires no further discussion at this point. My previous posts already showed your objections to be absolutely FALSE. Please study the subject first before pretending to be an expert.

where have i said ANYTHING about being an expert?!
did i give any links or provide any facts or figures to back up my "expert" opinion?
please make sure brain is engaged before opening mouth.

 

[Harmonic_Subset]

where have i said ANYTHING about being an expert?!
did i give any links or provide any facts or figures to back up my "expert" opinion?
please make sure brain is engaged before opening mouth.

You are a silly person trying to correct me. I am an expert. I WILL comment on technical subjects, and my brain is ALWAYS engaged. This will explain why, if you had taken more than 5 seconds to review this thread, there are mathematical formulas, and plenty of data to back up my assertions.

 

[Harmonic_Subset]

2inquisitive,

The economist article suggested that engineers eliminated the middle aisle normally found in city buses. It's possible that there is a door for every ROW of seats rather than a door for every seat. IMO that would work just as well. In fact, if the bus is just as wide as any bus, this may mean more seats per bus. On today's city buses people who are less able-bodied (elderly, obese, or disabled) are usually the ones sitting anyway, and fit healthy people relinquish their seats for them. So this new style of bus will benefit everyone. Seriously, nobody really wants to stand up while a bus is moving anyway, especially if it takes an hour to get where you are going.

With doors on both sides it might be necessary to limit stops to, say, stations that allow boarding on both sides. This isn't a problem on express routes between stations. But it might pose a small challenge for bus stops on street corners. Only doors on one side should be allowed to open in that case, for safety reasons. I'm sure most people wouldn't have too much trouble getting in and out. Movie theatres have a similar problem and most people manage just fine. I think this is a minor problem compared to the numerous serious problems with current buses, where people have to stand up, and where overcrowding slows boarding and traffic.

I picture a simple debit card payment system. It would no longer be the drivers' responsibility to collect fares. Each seat would have a swipe card device. The passenger would get in, sit down, and swipe his card. The device would instantly subtract the fare payment. If the passenger was making a long trip with several transfers along the way, the card would have a "transfer requested" binary switch. The passenger would hit the "Transfer" button before paying, swipe the card, and the device would turn off the tranfer switch instead of subtracting another fare. The driver would merely have to check a set of lights representing each seat. When all the lights turn green, all passengers have paid their fare, and the driver can then drive away. Doors can be manually or pneumatically closed. That is a minor issue as well.

Generally, people don't transport large items such as lawnmowers on a city bus. But I think you are referring generally to my idea that cars should be lighter, smaller, etc. IMO vehicles like SUVs and minivans will always exist. But as you can see, if you study my formula, such vehicles will never achieve the fuel economy of a lighter, smaller vehicle. The physics prohibits it. If you want to have a large family, or make a habit of carrying large amounts of cargo, this is a reality you have to accept. An SUV will always be a gas-guzzler compared to a smaller car. Whether I am a young person doesn't invalidate the fundamental physics. No matter how old or experienced you are, no matter how large a family you have, and no matter how large a home you have, the laws of the universe will never change. Ever.

 

[Stryder]

You've missed one important factor, 'Reduce the Distance'.

This is especially important for the US, unlike the UK it has an awful lot of space to expand into and this is seen with the ever increasing outlet stores that creep for miles out from major towns and cities.

To go shopping throughout all those outlets requires using a car to drive from one car park to another car park because of the overall distance. If the shops maintained proximity like they do in malls or even in High streets (Notibly in the UK they do anyway) the distance the car actually has to travel is greatly lessened.

Also traffic flow methods could be made 'Adaptive', having a central traffic report system telling you the quickest way home could in fact work out how to 'Balance' traffic through different routes so not everyone is trying to squeeze down one bottleneck. This would allow everyone to run at the governing Economy speed that most cars have without starting and stopping when the traffic comes to a halt.

In all it shouldn't be just about changing the Economy and Ergonomics of the Car alone, but to attempt to factor in all those things that make up our journeys.

 

[leopold]

harmonic_subset,
i was going to drop this subject but:

You are a silly person trying to correct me. I am an expert.

so, will you answer the following? and put your answer two ways
1. the weight of the object moved being the primary determiner.
2. the efficiency of the prime mover and rolling resistance being the primary determiner.
if weight is so important in figuring energy expenditures when moving an object from A to B as you claim it is then how does an astronaut move a 2 or 3 ton satellite like it was so much styrofoam?

 

[spidergoat]

A hybrid-electric bus isn't a bad idea. Using existing coachwork is more efficient than redesigning the entire bus. They don't travel fast enough to justify streamlining. I like the idea of a bus as a semi-trolley, recharging at intervals or just along certain roads.

Payment issues are solved in my area by the purchase of a monthly or yearly bus pass.

 

[Harmonic_Subset]

Take another look at this table of data (you may have to refresh your browser). At the bottom I've shown the predicted fuel consumption of buses, both commuter and city. It shows that even if a city bus makes stops every 1/2-kilometer, and never goes over 50 mph between stops, aerodynamic drag is still responsible for consuming 43 percent of the mechanical energy produced by the engine. For a commuter bus it is 82 percent of mechanical energy. In fact, I used identical buses for both applications, which means both lost substantially similar amounts of energy to aerodynamic drag, and the city bus simply consumed *additional* energy making all those extra stops. Hence, the total mechanical energy consumed by a city bus is nearly double that of a commuter bus. Therefore, I believe streamlining is justifiable for city buses. And the other benefits of a Superbus are pretty impressive too, such as not having to show your monthly bus pass to the driver and creating a huge lineup at the front door.

 

[Harmonic_Subset]

harmonic_subset,
i was going to drop this subject but:

so, will you answer the following? and put your answer two ways
1. the weight of the object moved being the primary determiner.
2. the efficiency of the prime mover and rolling resistance being the primary determiner.
if weight is so important in figuring energy expenditures when moving an object from A to B as you claim it is then how does an astronaut move a 2 or 3 ton satellite like it was so much styrofoam?

leopold99,

An object in space has no weight, only mass. The astronaut does not have to contend with friction or air resistance in orbit. And even in space a 2- or 3-ton satellite is as dangerous as a moving car if you get in its way. You can express the kinematics of a satellite in free-fall in terms of relative kinetic energy or momentum once you pick a reference point. I think I've answered your questions, although I have no way of knowing if you understood. A high school physics textbook would explain all these things.

 

[quadraphonics]

Take another look at this table of data (you may have to refresh your browser). At the bottom I've shown the predicted fuel consumption of buses, both commuter and city. It shows that even if a city bus makes stops every 1/2-kilometer, and never goes over 50 mph between stops, aerodynamic drag is still responsible for consuming 43 percent of the mechanical energy produced by the engine. For a commuter bus it is 82 percent of mechanical energy.

That sounds awfully high. Where did you get the coefficients of drag for the buses? I notice that the calculated and published values for MPG diverge pretty significantly for the case of buses.

 

[Harmonic_Subset]

That sounds awfully high. Where did you get the coefficients of drag for the buses? I notice that the calculated and published values for MPG diverge pretty significantly for the case of buses.

Yes, I noticed the divergence from published values for SUVs and trucks too. My opinion is that published values are exaggerated, or taken from track conditions. For example, people I've talked to often say that their truck is supposed to get 18 mpg, but when they drive they only get maybe 14 mpg. Fuel consumption of tractor-trailers is determined under track conditions, no bumps, no merging with traffic, no changes in speed. The drag coefficients are pretty well known, here is a list showing typical ranges of values. I've tried playing with the numbers, and in fact even significant reductions in drag coefficient do not bring the calculated mpg high enough to match the published values. Also, there is a huge difference in fuel consumption for buses depending on the application, i.e. commute between cities, or inner-city stop & go use. The fuel economy of the latter is substantially lower even though the published fuel consumption is exactly the same. Published values for trucks and buses are quite suspicious if you ask me.

 

[quadraphonics]

Yes, I noticed the divergence from published values for SUVs and trucks too. My opinion is that published values are exaggerated, or taken from track conditions.

Yes, that's certainly the case, but I wouldn't expect the difference to be so significant (the errors are in the hundreds of %s in the case of the buses). Also, I'm confused by your table of common coefficients of drag... how is it that an SUV has a lower coefficient than a formula 1 car, and that city buses differ so much from tractor-trailers? Looks fishy to me.

 

[Harmonic_Subset]

Yes, that's certainly the case, but I wouldn't expect the difference to be so significant (the errors are in the hundreds of %s in the case of the buses). Also, I'm confused by your table of common coefficients of drag... how is it that an SUV has a lower coefficient than a formula 1 car, and that city buses differ so much from tractor-trailers? Looks fishy to me.

Good questions! In Formula 1 racing, the cars have spoilers that create downforce and greater traction. This allows them to speed up and slow down and round corners with amazing precision. Unfortunately spoilers create as much drag as they create downforce. Similarly a wing at a high angle of attack will create both more lift, and more drag. The angle of the surface creates resultant forces: for a wing some of the resultant force is vertically upward and some of the resultant force is horizontally backward. A Formula One car compensates for the increased drag coefficient by being *extremely* low-slung. I mean, these cars are tiny. The driver is practically laying down on his back and sitting on the pavement. The frontal area has to be really small to benefit from the downforce of the spoilers and still have low overall drag.

You may have also noticed that a bus has a higher drag coefficient than the Empire State Building. I laugh at this, but it's true. For a skyscraper sometimes the wind is blowing on the corners and sometimes it is blowing on the flat sides. But for a bus the wind is always blowing against the flat front, just like a simple rectangular box. That is why, on average, a skyscraper is more aerodynamic than a bus.

You may also have noticed that a tractor trailer is more streamlined than a bus. Very old tractor-trailers might be similar to buses actually. I've seen some tractors from the 50s and 60s that had flat fronts. But these days it is common for the front of a tractor trailer to be shaped like the head of a dog, with the engine protruding (like a dog's snout), the windshield rising above that at an angle, and a wind faring smoothing the air flow above the cab toward the top surface of the trailer (which is taller than the cab without the faring). Some tractor trailers also have skirts along the sides of the trailer, and strakes (correct term?) at the back on the trailer to create a funnel of turbulent air that has slightly less suction on the flat back surface of the trailer. Overall, most modern tractor-trailers have a much lower drag coefficient than a bus. However, a tractor-trailer is extremely heavy, requiring upwards of 18 wheels to support the weight. Those 18 wheels create far more rolling friction than 4 wheels. This is reflected in my table of data where mechanical energy spent by a tractor trailer is split roughly 50-50 between rolling friction and aerodynamic drag.

This is why I say streamlining can benefit buses. IMO it would benefit any kind of vehicle. Additionally, the way most cars are made reducing the mass would also help since it tends to directly influence the frontal area, and that can reduce aerodynamic drag too, as well as the rolling friction and kinetic energy.

Seriously folks, this is the 21st century. We should all be driving cars that are sleek, lightweight, energy efficient, and high-tech. Instead some of the stuff I've been seeing on the roads would have been embarrassing 50 years ago.

 

[leopold]

leopold99,

An object in space has no weight, only mass. The astronaut does not have to contend with friction or air resistance in orbit. And even in space a 2- or 3-ton satellite is as dangerous as a moving car if you get in its way. You can express the kinematics of a satellite in free-fall in terms of relative kinetic energy or momentum once you pick a reference point. I think I've answered your questions, although I have no way of knowing if you understood. A high school physics textbook would explain all these things.

okay, let's forget about space.

scenario one.
you have a 3 ton car, the efficiency of the prime mover is 1%.
the rolling resistance is 99%
how much energy is going to be needed to move said car 1 mile.

scenario two
exact same conditrions as one but
the efficiency of the prime mover is 99%.
the rolling resistance is 1%.

 

[Harmonic_Subset]

okay, let's forget about space.

scenario one.
you have a 3 ton car, the efficiency of the prime mover is 1%.
the rolling resistance is 99%
how much energy is going to be needed to move said car 1 mile.

scenario two
exact same conditrions as one but
the efficiency of the prime mover is 99%.
the rolling resistance is 1%.

You can use my formula to calculate it.

 

[leopold]

You can use my formula to calculate it.

you said you was the expert. i want your expert answers.

 

[Harmonic_Subset]

leopold99,

You can use my formula to calculate it.

 

[leopold]

i get the impression your "expertise" is in copy/pasting from your daddys manuals.
that or you don't like the conclusions you are coming to.

 

[Harmonic_Subset]

Are you on drugs?!?

 

[Billy T]

...It's too bad I don't have ridership statistics or financial data for the Toronto Transit Commission. But I bet they wouldn't be very useful considering all the creative bookkeeping they are likely using to secure government grants, union contracts, and public support. I'd hate to be an accountant wading through that bloody mess....

You a slinging BS to avoid answering my post 17 questions, which have nothing to do with "ridership stastics." No accounting is needed to tell the number of seats and the gross weight of the supperbus. Also the price to purchase is something the compay sets. (I admit that the TTC may have gotten a special deal, but I am interested in the normal price I could buy one or a dozen for.)

Surely you can divide the weight by the number of seats.
Surely you can divide the price by the number of seats.

If not, supply the number of seats, weight and price and I will do it for you.