Flow over bicycle

Aim:To write the program that plots the graphs between:

1.velocity vs Drag force

2.Drag force vs Drag co efficient

Theory:The formulae used to calculate the drag force is

Drag Force =0.5*rho*A*v^2*c_d

where,

rho:Density

A:Frontal Area

v:Bicycle velocity

c_d:co-efficient of drag

where rho=1.2kg/m^3

A=0.1m^2

Procedure:The program to calculate the drag force vs velocity

"""
To calculate the drag force
By Sai Sarthak
"""
import math
import matplotlib.pyplot as plt

#inputs

#Drag of co-efficient
c_d=0.8

#Frontal area (m^2)
A=0.1

#Density (kg/m^3)
rho=1.2

#Bicycle velocity (m/s)
velocities=[5,6,7,8,9,10,11,12]
drag_forces=[]

for velocity in velocities:
drag_forces.append((0.5*rho*A*c_d*velocity*velocity))

print(drag_force)

Hence the drag force is calulated.

1.By using the python program,plot velocity vs drag force by varying velocity

"""
To calculate the drag force
By Sai Sarthak
"""
import math
import matplotlib.pyplot as plt

#inputs

#Drag of co-efficient
c_d=0.8

#Frontal area (m^2)
A=0.1

#Density (kg/m^3)
rho=1.2

#Bicycle velocity (m/s)
velocities=[5,6,7,8,9,10,11,12]
drag_forces=[]

for velocity in velocities:
drag_forces.append((0.5*rho*A*c_d*velocity*velocity))

plt.plot(velocities,drag_forces)
plt.xlabel('velocity')
plt.ylabel('drag_forces')
plt.show()

Here by varying the velocities the drag force is found

2.By using the python program,plot drag co-efficient vs drag force

"""
To calculate the drag force
By Sai Sarthak
"""
import math
import matplotlib.pyplot as plt

#inputs

#Frontal area (m^2)
A=0.8

#Density (kg/m^3)
rho=1.4

#Bicycle velocity (m/s)
velocity=20

#Drag o-efficients of different shapes (kgm/s^2)
c_ds=[1.51,1.12,0.98,0.35,1.62]

drag_forces=[]

for c_d in c_ds:
drag_forces.append((0.5*rho*A*c_d*velocity*velocity))

plt.plot(c_ds,drag_forces)
plt.xlabel('c_ds')
plt.ylabel('drag_forces')
plt.show()

Here by varying the co-efficient of drag the drag force is found.

Results:

1.The result of python program of plot velocity vs drag force

2.The result of python program of plot co-efficient of drag forces vs drag force

Conclusion:

1The program to plot velocity aganist drag force,done above was successfully exceuted with graphs.

2.The program to plot co-efficient of drag force aganist drag force was sucesfully exceuted with graphs.