volume delta calculator for piston engines

# -*- coding: utf-8 -*-
"""
volume delta calculator for piston engines
Created on Wed Jan 20 08:36:47 2016

@author: Jeffrey.Burdick
"""

from math import pi, cos, sin, radians, sqrt
import numpy as np
import pandas as pd

def positionPiston(radiusCrank, angleCrank, lengthRod ):
    return radiusCrank - lengthRod + radiusCrank *cos(angleCrank) + sqrt(lengthRod**2 - radiusCrank**2 *(sin(angleCrank))**2)

def volumeCylinder( area, length ):
    return area * length

def areaCircle( radius ):
    return pi * radius**2

def radiusCylinder( volume, length ):
    return sqrt( volume/(length * pi) )

lengthStroke = [ 65.8, 75, 79 ]
heightDeck = 201
heightPiston = 31.07 #not correct, but doesn't matter
boreLargest = 99.5
volumeTarget = volumeCylinder(
    area = areaCircle( radius = boreLargest/2 ),
    length = lengthStroke[0]
    )

lengthRod = [ heightDeck - heightPiston - i/2 for i in lengthStroke ]
boreCylinder = [ 2* radiusCylinder( volume = volumeTarget, length = i ) for i in lengthStroke ]

dataList = [ [
    volumeCylinder(
        area = areaCircle( boreCylinder[i] /2),
        length = positionPiston(
            radiusCrank = lengthStroke[i] /2,
            angleCrank = radians(j),
            lengthRod = lengthRod[i]
            )
        )
    for j in range(180) ] for i in range(len(lengthStroke)) ]

dataFrame = pd.DataFrame( { 'ej15': dataList[0], 'ej18': dataList[1], 'ej25': dataList[2] } )
dataFrame['ej15Delta'] = dataFrame['ej15'].diff()
dataFrame['ej18Delta'] = dataFrame['ej18'].diff()
dataFrame['ej25Delta'] = dataFrame['ej25'].diff()
dataFrame.to_csv('pistonMotionData.csv')