Program to calculate drag force against a cyclist

Program to calculate drag force against a cyclist.

Graph for Velocity vs Drag Force

Any object moving through a fluid experiences drag - the net force in the direction of flow due to pressure and shear stress forces on the surface of the object.

The drag force can be expressed as:

F_d = c_d 1/2 ρ v² A (1)

where

F_d = drag force (N)

c_d = drag coefficient

ρ = density of air(1.2 kg/m³ for air )

v = flow velocity (m/s)

A = characteristic frontal area of the body (m²)

The drag coefficient is a function of several parameters like shape of the body,Reynolds Number, Roughness of the surface etc.

The characteristic frontal area - A - depends on the body.

we can assume Drag coefficient for bicycle is 0.8 or 0.9

>> % inputs
>> % Drag Coefficient
>> c_d = 0.8

c_d =

0.8000

>>
>> % Area m^2
>> A = 0.1

A =

0.1000

>> % Density
>> % Density kg/m^3
>> rho = 1.2

rho =

1.2000

>> % Velocity
>> v = 1

v =

1

>> % Velocity
>> v = [1:50];
>> drag_force = rho*A*v.^2*c_d*0.5;

>> plot(v, drag_force);
>> xlabel(\'velocity\')
>> ylabel(\'Drag Force\')
>> grid on

I got errors due to wrongly typed code and due to undefined function and variable.