FLOW OVER A BICYCLE

FLOW OVER A BICYCLE

Introduction: whenever you ride a bicycle you experience a force which resist motion of bicycle. This problem mainly arises due to wind resistance. In order to move further riders has to push further through the mass of air so you experience a retarding force. OBJECTIVES 1.To calculate drag force on a cyclist. 2.To draw a plot between drag force and velocity. 3.To draw a plot between drag force and drag coeffiecient.

PROCEDURE

MATHEMATICAL FORMULA

Drag_force=(0.5*rho*A*c_d.*v.^2)

where: rho=density of air (in kg/m^3)

A=frontal area(in m^ 2)

c_d=coefficient of drag

v=velocity of moving body(in m/s)

ROGRAM FOR FLOW OVER A BICYCLE

%program to calculate drag force on a bicycle rider and for plotting between velocity vs drag force and drag force vs drag coefficient.

close all
clear all
clc

%inputs

%drag coefficients

c_d=[1:50]

%area

A=0.1

%density

rho=1.2

%velocity

v=[1:50]

drag_force=rho*A*c_d.*v.^2*0.5

%plotting

%plot for velocity vs drag force

figure(1)
plot(v,drag_force,'color','b')
xlabel('velocity')
ylabel('Drag force')
grid on

%plot for drag force vs drag coefficient
figure(2)
plot(drag_force,c_d,'color','r')
ylabel('drag coefficients')
xlabel('Drag force')
grid on

EXPLANATION:

In the above code we take drag coefficient(c_d),velocity(v),density(rho),frontal area(A) as the input and by putting respective values in drag force formula we calculated the drag force as per requirementi i.e for different values of velocity and drag coefficients. Then we plot two curves one between velocity and drag force and other between drag force and drag coefficient.

Errors occured while coding:

during coding i face two problems one is that i forgot to write (.) in the drag force formula and second one is intead of writing xlabel and ylabel i wrote xlable and ylable due to which labels are not shown.

CONCLUSION:

1.From the velocit vs drag force curve it is concluded that as the velocity increases drag force will also increases and it will increases exponentially and shape of curve is parabolic.

2.From the drag force vs drag coefficient curve it can be concluded that more the value of drag force more will be the drag coefficient.

PLOT LINKS:

https://drive.google.com/open?id=1R7GOA5sRBz1i--4laDWyrMuRlltDqt0t

https://drive.google.com/open?id=1FoUr6RdYaRtCpgwCVqOVFhb8I6ZOUIVu