Air standard Cycle

"""
 OTTO CYCLE SIMULATOR

"""

import math
import matplotlib.pyplot as plt

def engine_kinematics(bore,stroke,con_rod ,cr,start_crank,end_crank):

    """
    Engine Kinematics

    """
    

    #geomentric paramaters

    a = stroke/2
    R = con_rod/a

    # volume parameters 
    v_s = math.pi*(1/4)*pow(bore,2)*stroke
    v_c = v_s/(cr-1)


    sc = math.radians(start_crank)
    ec = math.radians(end_crank)
    
    num_values = 50
    
    dtheta = (ec-sc)/(num_values-1)
    V = []
    for i in range (0,num_values):
        theta = sc = i*dtheta
        term1 = 0.5*(cr-1)
        term2 = R+1 - math.cos(theta)
        term3 = pow(R,2) - pow(math.sin(theta),2)
        term3 = pow(term3, 0.5)
    
        V.append(( 1 + term1*(term2 - term3))*v_c)
    
    return V   
 
#Input
p1 = 101325
t1 = 500
gamma = 1.4
t3 = 2300

#geomentric values
bore = 0.1
stroke = 0.1
con_rod = 0.15
cr = 12

#volume calculation
v_s = (math.pi/4)*pow(bore,2)*stroke
v_c = v_s/(cr-1)
v1 = v_c+v_s

# state point 2
v2 = v_c

# p2v2^gamma = p1v1^gamma
p2 = p1*pow(v1,gamma)/pow(v2,gamma)

# p2v2/t2 = p1v1/t1 | rhs = p1v1/t1 | p2v2/t2 | t2 = p2v2/rhs
rhs = p2*v1/t1
t2 = p2*v2/rhs
V_compression = engine_kinematics(bore, stroke, con_rod, cr, 180,0)

constant = p1*pow(v1,gamma)

P_compression = []

for V in V_compression:
    P_compression.append(constant/pow(V,gamma))
    

#state point 3
v3 = v2

# p3v3/t3 = p2v2/t2 | rhs = p2v2/t2 | p3 = rhs*t3/v3
rhs = p2*v2/t2
p3 = rhs*t3/v3
V_expansion = engine_kinematics(bore, stroke, con_rod, cr, 180,0)

constant = p3*pow(v3,gamma)

P_expansion = []

for V in V_expansion:
    P_expansion.append(constant/pow(V,gamma))
    
#state point 4
v4 = v1

#p4v4^gamma = p3v3^gamma
p4 = p3*pow(v3,gamma)/pow(v4,gamma)

#p4v4/t4 = rhs
t4 = p4*v4/rhs

plt.plot([v2,v3,v4,],[p2,p3,p4])
plt.plot(V_compression,P_compression)
plt.plot(V_expansion,P_expansion)
plt.plot([v4,v1],[p4,p1])
plt.show()