Formula to Calculate Vehicle Momentum Energy?

not sure about the formula for energy/=mass ,, but not sure if having the trailer push you is a good idea,, what if your turning as you start,, will it push you sideways? would have to be a controled push/acelerate? but a good idea to recoop the energy in stopping, might look at some of the hybird cars,, they use this to store back in to the batterys but by reversing the dc motors so to speak,, good luck

Thanks for the reply. The area of how to reapply the energy is one of the problems to be worked out. One of the ways we are thinking of is to make the trailer wheels try to spin, like a little coil spring on a wind up car or a garage door spring which would help lighten the load for pulling the trailer. All of which would be controled in the pulling vehicle. Thanks Scott

mass x differential speed

E = 1/2 MV squared. That is the total energy in the system the time or distance merely affects the recovery rate dE/dT. The dE/dT will be important in the sizing of any harvesting device. The total E determines the storage capacity required so does the number of stops that will be stored. Motors don't need to be DC 3 phase squirrel cage motors regenerate exceptionally well and are current technology in locomotive and mining applications. Agree on the trailer pushing problems, would be useful as trailer brake but energy should be fed further forward for acceleration.

I suspect that having a trailer "push" you is not a good thing. Would be a disaster in icy conditions - and would be troublesome in any other condition than straight ahead acceleration. Better to have the energy accumulator on the tow vehicle than the trailer where application of power can more closely controlled.

From one D+ to another. Grades aren't everything. I did some work for the student launch program in school. Moment of inertia is calculated by multipling the mass times the acceleration or how quickly you change velocity. So, keep in mind time is a factor in your calculation. In the trailer on the hill situation you not only have the 80 to 60mph acceleration but also the acceleration of gravity to account for as well 9.8m/sec^2 or something like that. remember it is reduce by friction with the road and the grade of the hill. I agree with the others a pushing trailer is not a good thing. Take from one who drove from Vermont to California towing a pretty heavy trailer. Even on dry roads going straight it gets hairy when your trailer is pushing you. Good luck, WC

Good idea Scott: Here is how to do it. Use DC generator/motors on each Wheel, wired to storaged battries. Controled by alternator switch. A tongue senser switch ( three position)(charge,netrul discharge)would be your controler. Pull on the slip tongue and the motor would supply turning power to the wheels. Push the slip tongue together and charge the storage batteries. Del www.co-engineering.net

just some brainstorming ideas..... fist one, is to use the mechanical energy of the trailer axle to generate electricity, for use in an electrical motor. this is the same idea as the hybrid cars. Second one, is to store energy by mechanical means. using a torsion spring mounted in the axle, with a clutch and gear box. when the brake is being applied, the spring will be preloaded, ie, turn in the opposite direction of the wheel. when the brake is released, the spring is released and therefore turing in the same direction as the wheel to provide the wheel/axle energy for acceleration. The clutch will be used as a selector when switching between energy store mode and energy release mode. The direction of the spring rotation relative to the axle can be controlled by the gear box.

Neglecting the rotational energy of the wheels, the recoverable energy is: E=1/2*M*(DeltaV)^2, where M(kg)is the mass, DeltaV = differential (initial minus final) speed in m/s, E in joule. Energy can be retrieved also in downhill roads (gravitational to electrical), method already exploited (at least 60-70 years) by trains in mountain.

Another storage device is the flywheel. It has been used successfully in several experimental vehicles. The idea is that a frictionless, high mass flywheel can absorb and store kinetic energy through a series of gears and clutches (like an automatic transmission) during braking, then release the energy back to the drive wheels during acceleration. This is probably more practical and safer than the spring idea and more efficient than the motor/generator idea where energy is lost to heat during the mechanical/electrical conversion process (both ways).

Advances in Continuously Variable Transmission (CVT) technology being used in several small cars today should make flywheel braking even more practical and efficient.

Hi there, My final project for 4th year mechanical engineering was on regenerative braking. We investigated several systems and came up with a conclusion on each method of storing this recuperated energy: batteries (bad. heavy, expensive, short life) flywheel (bad. An ENORMOUS wheel would need to spin at speeds so high that only the best titanium or carbon fiber structure could handle the centrifugal forces) supercapacitors (okay. New tech' so it's still a bit pricey but they are kind of the opposite of normal capacitors which have high voltages and low currents...supercap's have high current and low voltage, not to mention that they are quite compact and can be charged/discharged many more times than batteries.) Hydraulic (good. Ford made a prototype called the Tonka which used "Hydraulic Launch Assist" http://www.pickuptruck.com/html/autoshows/naias200 2/ford/tonka.html ) We ended up using the hydraulic solution since the equipment involved was already available in the market and just needed to be properly sized for the vehicle we were using. Essentially a hydraulic pump/motor is attached to the drivetrain somewhere, either at the motor or, as we chose, at the driveshaft of the vehicle. A hydraulic system catches the energy of the vehicle by spinning the pump (using the momentum of the car) and pumping hydraulic fluid into a nitrogen filled tank, which pressurizes. This pressure can be bled back out through the motor to make the vehicle start moving again. The Ford Tonka was able to stop for something like 60mph and, using only the recuperated energy, accelerate to 35mph. This essentially skips the first few gears on the transmission so fuel economy goes up quite significantly if you can put'er straight into overdrive and cruise away.

Thank you all for such good and practical advice and solution's to my math problem's. I also don't think that pushing a vehicle with the trailer wheels in direct drive is a good idea in a lot of situations, although there is a hydraulic drive unit on the market that delivers power from the engine to the trailer wheels, I'm not sure who uses it. My thinking also comes from delivering heavy trailer loads of lumber with an underpowered truck. So often I would start from a stop going up a slight incline and if I had just a little more power to get moving it would be wonderful. Rather than a direct drive to the trailer wheel we would apply a spinning action to the trailer wheels, just enough to help the truck get back up to speed but not actually be the driving wheels. The driver will controle wheather the spinning action will be engaged or not. We have had good results on a scale model winding rubber cords in diferent configurations and releasing the energy back to the wheels. You are all so helpfull. Thanks Scott

hi