Do you have a video for longitudinal forces? I'm trying to figure out the acceleration profile of a vehicle that has load transfer onto the rear tires. The equations are fairly straight forward but I keep getting a recursive answer where the maximum acceleration keeps increasing as long as the traction motor can apply more torque. This shouldn't be the case, any advice?
wdf - Front weight distribution%/100, wdr - 1 - wdf mt - total car mass in kg g - acceleration due to gravity (m/s2) Faero_f - Front aero Force (N) Faero_r - Rear aero Force (N) Fyf/Fyr - Front/Rear lateral force at axle (N) prr - Lateral load transfer at front. h - c.g height (m) tm - Mean track (m) I hope this helps.
+Akshay Roge There are a couple of ways you can measure c.g height. You can either prop the front up and by noticing the difference in the scale readings calculate it that way. Alternatively put the car on an angle and rotate it until it is just balancing. The formula for that is cg_height = (0.5*tm)*tan(90 - roll_angle). Here tm is the mean track, and the roll angle is the angle to the ground where it is just balancing. In terms of some rough numbers, open wheelers/LMP1/LMP2 are about 0.3m, GT cars are about 0.4-0.5m. Road cars are in the order 0.4-0.7m. I hope this helps!
Akshay - what I mean by the roll angle of the kart is when you angle it on it's side to determine the c.g height. Much like you see with stunt drivers in the movies. Given this is a kart you should actually get a really good measure of it. Just put the driver weights in the seat.
Sorry for troublesome but still the question remains, i haven't manufactured my kart yet ,for this I need to do lots of calculation to design my chassis and for that I need to decide my CG location. Summing up I want to calculate my CG location theoretically since I don't have kart.
Now it becomes clear! Sorry mate. Calculating cg height is easy here's the formula, cg_height = sum of(h_element*m_element)/total mass What you are doing is taking the mass of all the elements, measuring them with respect to the ground. Multiply these all up and then divide by the total mass and you are done.
Do you really need a spreadsheet to tell you that a 20% change in rear bar stiffness will make more of a difference than a 7% change in spring stiffness?
Hey mate - lateral acceleration is a consequence and should come from the data. However if you know the corner radius ay = (Vx*Vx)/R where Vx is the corner speed in m/s and R is the corner radius in m.
@@5432Krishna Hey mate remember lateral acceleration is a by product of the lateral forces applied to the vehicle. If you think of it this way it will make your like a lot easier.
Thank you, this is what I was looking for!
Thanks a lot for posting this!
Could you define the variables for the tyre load approximation?
Do you have a video for longitudinal forces? I'm trying to figure out the acceleration profile of a vehicle that has load transfer onto the rear tires. The equations are fairly straight forward but I keep getting a recursive answer where the maximum acceleration keeps increasing as long as the traction motor can apply more torque. This shouldn't be the case, any advice?
Drink everytime you hear the word "basically"! 😁 Joke asides, awesome video! Thanks!
wdf - Front weight distribution%/100,
wdr - 1 - wdf
mt - total car mass in kg
g - acceleration due to gravity (m/s2)
Faero_f - Front aero Force (N)
Faero_r - Rear aero Force (N)
Fyf/Fyr - Front/Rear lateral force at axle (N)
prr - Lateral load transfer at front.
h - c.g height (m)
tm - Mean track (m)
I hope this helps.
Thnaks a lot for this vd...Can u please tell me how did you calculate height of CG and finally how to decide its location?
+Akshay Roge There are a couple of ways you can measure c.g height. You can either prop the front up and by noticing the difference in the scale readings calculate it that way. Alternatively put the car on an angle and rotate it until it is just balancing. The formula for that is cg_height = (0.5*tm)*tan(90 - roll_angle). Here tm is the mean track, and the roll angle is the angle to the ground where it is just balancing. In terms of some rough numbers, open wheelers/LMP1/LMP2 are about 0.3m, GT cars are about 0.4-0.5m. Road cars are in the order 0.4-0.7m. I hope this helps!
thankx for your positive response
actually I haven't manufacture my kart yet. I'm still in my design process...so how do I find roll angle of my kart?
Akshay - what I mean by the roll angle of the kart is when you angle it on it's side to determine the c.g height. Much like you see with stunt drivers in the movies. Given this is a kart you should actually get a really good measure of it. Just put the driver weights in the seat.
Sorry for troublesome but still the question remains, i haven't manufactured my kart yet ,for this I need to do lots of calculation to design my chassis and for that I need to decide my CG location.
Summing up I want to calculate my CG location theoretically since I don't have kart.
Now it becomes clear! Sorry mate. Calculating cg height is easy here's the formula,
cg_height = sum of(h_element*m_element)/total mass
What you are doing is taking the mass of all the elements, measuring them with respect to the ground. Multiply these all up and then divide by the total mass and you are done.
Do you really need a spreadsheet to tell you that a 20% change in rear bar stiffness will make more of a difference than a 7% change in spring stiffness?
IF YOU SAY BASICALLY ONE MORE TIME IM GOING TO BLOW MY HEAD OFF
So noted my friend, but focus on the content.
lol!
could you please tell how to calculate lateral acceleration
Hey mate - lateral acceleration is a consequence and should come from the data. However if you know the corner radius ay = (Vx*Vx)/R where Vx is the corner speed in m/s and R is the corner radius in m.
@@ChassisSim isn't this the the counter for centrifugal force acting on vehicle during cornering
@@5432Krishna Hey mate remember lateral acceleration is a by product of the lateral forces applied to the vehicle. If you think of it this way it will make your like a lot easier.