Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Full-boat-tail trailer with gap-fillers for Toyota T-100 pickup

aerohead · 03-31-2012, 03:17 PM

*I'm posting 8-new pictorial drag tables up in #248 permalink which will keep the 10-newest images together.
*By comparing the 'anatomy' of the different configurations and inspecting their respective drag coefficients,you can discern the difference how certain features impact aerodynamic drag.
*Most of the numbers are straight out of the wind tunnel.I did interpolate or extrapolate a few values based on drag curves constructed from published data for configurations not 'broken out' in the original studies.
*If you have the original 'Figures' used in the developments,you'll understand where 'I was going.'
*The last 2- tables are specific to the trailer project and by inspecting all 10-tables and cross-referencing them,you should be able to understand the linear thought progression leading up to the invention of the trailer.
*Abbott and Von Doenhoff's wing work establishes the significance of a 'gap' and its impact as a function of size and position along the airfoil.These values can be 'seen' within the railroad,drafting,convoy,and trailer images.
*When NASA gap values are considered with respect to the 'Standard' locomotive railroad train,you'll see tight correlation to the 3-bus convoy drag of #2 & #3 bus.
* Base drag of tail cars on trains can be deduced from drag of leading car vs tail car and vary as a function of surface quality,surface friction and boundary layer effects.Base drag IS the Cd of the wake turbulence itself.
*I've mixed buses and rail cars together.The air doesn't care.It's all the same as far as fluid mechanics goes.
*On line #6 of the railroad components table you will see a self-powered passenger rail car of 'Ideal' form with theoretical drag minimum of Cd 0.08.This form is remarkably like the aero-modded JEEP Cherokee vs Prius in the Stunt-Busters episode thread.
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There's always more to add,but I need to take some time to deal with Caesar ,domestic engineering,and femme-bot.And Bonneville.
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These 10-tables should arm you with enough data to be dangerous.They required 96 man-hours to put together,or over the cost of 19 of Hucho's books.
If you don't have Hucho's book.Get one.
If you'll eat dry dog food for one week,you can save enough in groceries to cover the cost of the book.Once you have his book,you'll be able to save enough to eat caviar if you like,which will easily take the taste of dog food out of your mouth.Your health won't suffer.I know this for a fact.

03-31-2012, 03:17 PM	#256 (permalink)
aerohead Master EcoModder Join Date: Jan 2008 Location: Sanger,Texas,U.S.A. Posts: 15,895 Thanks: 23,972 Thanked 7,223 Times in 4,650 Posts	8-new pictorial tables I'm posting 8-new pictorial drag tables up in #248 permalink which will keep the 10-newest images together. By comparing the 'anatomy' of the different configurations and inspecting their respective drag coefficients,you can discern the difference how certain features impact aerodynamic drag. Most of the numbers are straight out of the wind tunnel.I did interpolate or extrapolate a few values based on drag curves constructed from published data for configurations not 'broken out' in the original studies. If you have the original 'Figures' used in the developments,you'll understand where 'I was going.' The last 2- tables are specific to the trailer project and by inspecting all 10-tables and cross-referencing them,you should be able to understand the linear thought progression leading up to the invention of the trailer. Abbott and Von Doenhoff's wing work establishes the significance of a 'gap' and its impact as a function of size and position along the airfoil.These values can be 'seen' within the railroad,drafting,convoy,and trailer images. When NASA gap values are considered with respect to the 'Standard' locomotive railroad train,you'll see tight correlation to the 3-bus convoy drag of #2 & #3 bus. Base drag of tail cars on trains can be deduced from drag of leading car vs tail car and vary as a function of surface quality,surface friction and boundary layer effects.Base drag IS the Cd of the wake turbulence itself. I've mixed buses and rail cars together.The air doesn't care.It's all the same as far as fluid mechanics goes. On line #6 of the railroad components table you will see a self-powered passenger rail car of 'Ideal' form with theoretical drag minimum of Cd 0.08.This form is remarkably like the aero-modded JEEP Cherokee vs Prius in the Stunt-Busters episode thread. ------------------------------------------------------------------------- There's always more to add,but I need to take some time to deal with Caesar ,domestic engineering,and femme-bot.And Bonneville. -------------------------------------------------------------------------- These 10-tables should arm you with enough data to be dangerous.They required 96 man-hours to put together,or over the cost of 19 of Hucho's books. If you don't have Hucho's book.Get one. If you'll eat dry dog food for one week,you can save enough in groceries to cover the cost of the book.Once you have his book,you'll be able to save enough to eat caviar if you like,which will easily take the taste of dog food out of your mouth.Your health won't suffer.I know this for a fact.