#include <stdio.h>
#include <math.h>
#include "UnitConversion_winters0.h"

/* PA 5.2.1 Task2: Heat loss from a house
* File:      PA_5_2_1_Task2_winters0.c
* Date:      15 February 2012
* By:        Colleen Winters
* Login:     winters0
* Section:   3
* Team:      46
*
* ELECTRONIC SIGNATURE
* Colleen Winters
*
* The electronic signature above indicates the program submitted for
* evaluation is my individual work, and I have a general understanding of
* all aspects of its development and execution.
*
* PROGRAM DESCRIPTION
*  Find the heat lost from a house in keeping the house at a constant temperature.
*/


/* Defined variables */

/* gravity */
#define g 9.81

/* Prandtl number */
#define Pr .7

/* Kinematic viscosity of air */
#define y .0000178

/* thermal conductivity of air */
#define K .25


/* --- functions prototypes --- */
float Rayleigh( float Th, float Te, float L);
float HeatLoss( float L, float W, float Th, float Te, float HeTrans);
float Nusselt( float Ra);
float HeTrans( float Nusselt, float L);



int main(void)
{
/* ---- Variable declaration ---- */


/* L = height, W = length */
float TempH, TempE, L, W;

/* storage for outputs from functions */
float Ra, HL, Nu, TCo;

/* ---- Input section ---- */

printf("\nThis function takes the user inputs to find the heat loss from a \
house due to the difference in the temperature inside and outside.\n");

printf("\nInput temperature of the house in F: \n");
scanf("%f", &TempH);
printf("Input temperature outside in K: \n");
scanf("%f", &TempE);
printf("Input the height of the house in feet: \n");
scanf("%f", &L);
printf("Input the total length of the house in feet: \n");
scanf("%f", &W);

/* ---- transforming variables into proper units ---- */

TempH = Fahr2Kel(TempH);
L = Ft2M(L);
W = Ft2M(W);

/* ---- storage of calculated values from functions. ---- */

Ra = Rayleigh(TempH, TempE, L);
Nu = Nusselt(Ra);
TCo = HeTrans(Nu, L);
HL = HeatLoss(L, W, TempH, TempE, TCo);

/* ---- Output section ---- */

printf("\nRayleigh = %f ", Ra);
printf("\nNusselt = %f ", Nu);
printf("\nHeat Transfer coeff = %f", TCo);
printf("\nThe amount of heat lost from a house is %.6f BTU/s\n", HL);
return 0;
}


/* --- Called functions --- */



float Rayleigh( float Th, float Te, float L)
{
/* --- Variable declaration --- */
float Ra;

/* --- Calculations --- */

Ra = (g * ((Th - Te)/Te) * pow(L , 2.0) * Pr);
Ra = Ra / pow(y , 2.0);

return Ra;
}



float Nusselt( float Ra)
{
/* --- Variable declaration --- */
float Nu;

/* --- Calculations --- */

Nu = .59 * pow(Ra , .25);

return Nu;
}


float HeTrans( float Nusselt, float L)
{
/* --- Variable declaration --- */
float TCo;

/* --- Calculations --- */

TCo = (Nusselt * K) / L;

return TCo;
}


float HeatLoss( float L, float W, float Th, float Te, float HeTrans)
{
/* --- Variable declaration --- */
float Q;

/* --- Calculations --- */

Q = HeTrans * L * W * (Th - Te);

return Q;
}