changed code for ffffg

Author: ndanilo8

.gitignore

@@ -0,0 +1,2 @@
+*.exe
+.vscode

ejectionChargeCalculator.cpp

@@ -4,52 +4,71 @@ E-mail: [email protected]
 */
 #include <iostream>
 #include <cmath>
-
 using namespace std;
 
-double calculatePyrotechnicCharge(double volume, double pressure, double temperature, double heightAboveSeaLevel)
+
+const double pi = 3.14159;
+const double gm_to_lbs = 1.0 / 453.593;
+const double cm_to_inch_conversion = 0.393701; // 1 cm = 0.393701 inches
+const double B = 22.16 * 12.0; // in-lbf/lbm
+const double T = 3307.0; // Combustion temperature of FFFFg in degrees R
+
+// Function to calculate the volume of a cylinder
+double calculate_cylinder_volume(double diameter_in_inches, double length_in_inches)
+{
+    // Convert diameter to radius in inches
+    double radius_in_inches = diameter_in_inches / 2.0;
+
+    // Calculate volume in cubic inches
+    double volume_in_cubic_inches = pi * pow(radius_in_inches, 2) * length_in_inches;
+
+    return volume_in_cubic_inches;
+}
+
+// Function to calculate the grams of FFFFg black powder
+double calculate_black_powder_grams(double pressure_in_PSI, double diameter_in_inches, double length_in_inches)
 {
-    // Constants
-    const double gasConstant = 8.314;      // Universal gas constant [J/(mol*K)]
-    const double standardTemperature = 288.15; // Standard temperature at sea level [K]
-    const double molarMassAir = 0.02897;   // Molar mass of dry air [kg/mol]
-    const double specificGasConstant = gasConstant / molarMassAir; // Specific gas constant for dry air [J/(kg*K)]
-
-    // Adjust temperature and height above sea level
-    double temperatureInKelvin = temperature + 273.15;
-    double adjustedPressure = pressure * exp(-heightAboveSeaLevel / (specificGasConstant * temperatureInKelvin));
-
-    // Calculate the amount of pyrotechnic charge needed in moles
-    double pyrotechnicChargeMoles = (volume * adjustedPressure) / (specificGasConstant * temperatureInKelvin);
-
-    // Convert moles to grams using the molar mass
-    double pyrotechnicChargeGrams = pyrotechnicChargeMoles * molarMassAir;
-    return pyrotechnicChargeGrams;
+    double pressure_in_lbf_per_inch2 = pressure_in_PSI; // The input pressure is already in lbf/in^2
+
+    // Calculate the volume of the cylinder in cubic inches
+    double volume_in_cubic_inches = calculate_cylinder_volume(diameter_in_inches, length_in_inches);
+
+    // Calculate the constant z
+    double z = 1.0 / (gm_to_lbs * B * T);
+
+    // Calculate the final charge in grams
+    double final_charge_grams = pressure_in_lbf_per_inch2 * volume_in_cubic_inches * z;
+
+    return final_charge_grams;
 }
 
 int main()
 {
-    // User inputs
-    double containerVolume, requiredPressure, expectedTemperature, heightAboveSeaLevel;
+    // User input
+    double diameter_in_cm;
+    double length_in_cm;
+    double diameter_in_inches;
+    double length_in_inches;
+    double pressure_in_PSI;
 
-    // Get user inputs
-    cout << "Enter the container volume (in cubic meters): ";
-    cin >> containerVolume;
+    cout << "Enter the diameter of the parachute section body tube (in cm): ";
+    cin >> diameter_in_cm;
 
-    cout << "Enter the required pressure (in Pascals): ";
-    cin >> requiredPressure;
+    cout << "Enter the length of the parachute section body tube (in cm): ";
+    cin >> length_in_cm;
 
-    cout << "Enter the expected temperature (in Celsius): ";
-    cin >> expectedTemperature;
+    cout << "Enter the desired pressure in PSI: ";
+    cin >> pressure_in_PSI;
 
-    cout << "Enter the height above sea level (in meters): ";
-    cin >> heightAboveSeaLevel;
+    // cm to inches
+    diameter_in_inches = diameter_in_cm * cm_to_inch_conversion;
+    length_in_inches = length_in_cm * cm_to_inch_conversion;
 
-    // Calculate the pyrotechnic charge in grams
-    double chargeAmountInGrams = calculatePyrotechnicCharge(containerVolume, requiredPressure, expectedTemperature, heightAboveSeaLevel);
+    // Calculate the grams of FFFFg black powder
+    double black_powder_grams = calculate_black_powder_grams(pressure_in_PSI, diameter_in_inches, length_in_inches);
 
     // Display the result
-    cout << "The amount of pyrotechnic charge needed is: " << chargeAmountInGrams << " grams" << endl;
+    cout << "Grams of FFFFg Black Powder: " << black_powder_grams << " grams" << endl;
 
     return 0;
 }