Drag force calculation on an object using Matlab

Aim = Write a Matlab program to calculate drag force against a cyclist.

Introduction =

Every object which moves through air is subjected to drag force.
The formula for drag force is given as-

Drag force = `1/2*rho*v^2*A*C_d`

where,F = Drag force experienced by the cyclist due to relative air. (`kg m/sec`)

`rho` = density of air [`(kg)/(m^3)`]

v = velocity `(m/sec)`

A = Frontal area of the cyclist. `m^2`

C_d = Coefficient of Drag ( unitless)

Code for Matlab program to generate Velocity vs Drag force plot is as follows=

"Linspace" = this command generates an array of values specified between two values.

"plot" = this command generates a plot when x and y values are provided in the paranthesis.

% Air Flow over a Bicycle.
% Velocity vs Drag Force

clear all
close all
clc

% Inputs

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

% Area (m^2)
a = 1

% Velocity (m/s)
v = linspace(1,50,50); %we are finding the drag force for each values generated for velocity by "linspace" command.

% Drag co-efficient
c_d = 3;

% Drag Force (kg-m/s^2)
drag_force = 0.5*rho*a*v.^2*c_d;

plot(v,drag_force);
xlabel('Velocity');
ylabel('Drag Force');
grid on
title('Velocity vs Drag force')

the plot is as follows= figure (1)

Code for Matlab program to generate Coefficient of drag vs Drag force plot is as follows=

% Air Flow over a Bicycle.
% Coefficient of drag vs Drag Force

clear all
close all
clc

% Inputs

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

% Area (m^2)
a = 1

% Velocity (m/s)
v = 2

% Drag co-efficient
c_d = linspace(0.47,1.15,50); % considering various values of coefficient of drag between 0.47 and 1.15


% Drag Force (kg-m/s^2)
drag_force = 0.5*rho*a*v.^2*c_d;

plot(c_d,drag_force);
xlabel('C_d');
ylabel('Drag Force');
grid on
title('Coefficent of Drag vs Drag force')

the plot is as follows= figure (2)

Conclusion =

As per the figure(1) ,we can see that the Drag force increases exponentially, and the Drag force increases in linear manner with respect to coefficient of drag in figure (2).