| Re: Brian Beckman's:The Physics of Racing |
Subject: Re: Brian Beckman's:The Physics of Racing by BrianCunningham on 2014/3/4 1:54:42 Doing some physics analysis to see if I can improve my times at the autocross. 1st run through is a simple circle. 1 foot/second = 0.682 mile/hour (mph) lateral G Assuming: 1 G lateral grip 1 G braking max and 1 G acceleration, keeps it simple and it matches my 60ft times. a=v^2/r a*r=v^2 v=sqrt(a*r) Gives me the max speed in a turn c=2*pi*r t=c/v Give me the distance covered and the time it takes to cover it. As predicted the smaller the circle the better for turning direction, though the speed is kept low.  Next up, A SIMPLE SLALOM. The curve is dictated by how far the cones are set apart, the width of the car, and how close the driver can get to the cone.  I ran three slaloms 25ft, 50ft, and 100ft separation. with the car's center being 4ft and 3.5ft from the cone @ apex. As you can see being closer to the makes a big difference. The distance is about the same, but the speed is higher.  Next up, AN S TURN I first calculated the distance between the cones as a reference even though you could never make the corner that way, it shows what the absolute minimum distance would be. Next I used an s-curve to find out what the max radius the element could be taken This gives the speed that would be used throughout the element. It also gives the entrance and exit speeds The car's turning radius gives the path with the shortest drivable distance. A straight is used to connect the two curves. The turning radius give the max speed in those two curves, the entrance and exit speeds. The straight line between is used for acceleration and then braking. I also ran a curve with slightly wider turns at the corners. Times are then calculated.    |
