Proposal to be a little more OOP

[Brennan1994]

McCormackScheme/McCormackScheme/McCormackScheme/Program.cs

Lines 6 to 29 in cf6cf55

	Console.WriteLine("Welcome to the McCormack Scheme Console App");
	Console.WriteLine("What is the bed slope?");
	double bedSlope = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is Manning's N?");
	double n = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the initial velocity?");
	double initialVelocity = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the channel bottom width?");
	double bottomWidth = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the bank slope?");
	double bankSlope = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the initial Depth?");
	double initialDepth = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the gravitational constant?");
	double g = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the time step?");
	int timeStep = Convert.ToInt32(Console.ReadLine());
	Console.WriteLine("What is the computational interval of distance?");
	double distanceStep = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the simulation time period?");
	double totalTime = Convert.ToDouble(Console.ReadLine());
	Console.WriteLine("What is the length of the channel?");
	double channelLength = Convert.ToDouble(Console.ReadLine());

Consider saving these inputs into separate objects. If I were to steal shamelessly from RAS's design, I'd say you have an initial conditions object, a computational settings object, and a geometry object.

You could then put these static methods into those objects as private functions, referencing properties instead of all parameter inputs, which might make your project a little cleaner. Could also keep them static. stylistic choice.

McCormackScheme/McCormackScheme/McCormackScheme/Calculate.cs

Lines 14 to 55 in cf6cf55

	public static double ManningsFrictionSlope(double depth, double bottomWidth, double bankSlopeHorizontalToOne, double velocity, double manningsN, double k)
	{
	double hydraulicRadius = TrapezoidalArea(depth, bottomWidth, bankSlopeHorizontalToOne) / TrapezoidalWettedPerimeter(bottomWidth, depth, bankSlopeHorizontalToOne);
	return (Math.Pow(velocity, 2) * Math.Pow(manningsN, 2)) / (Math.Pow(k, 2) * Math.Pow(hydraulicRadius, (4 / 3)));
	}
	public static double ManningsFrictionSlope(double velocity, double depth, double manningsN, double bankSlopeHorizontalToOne)
	{
	return (Math.Pow(velocity, 2) * Math.Pow(manningsN, 2)) / HydraulicRadius(depth, bankSlopeHorizontalToOne);
	}
	public static double HydraulicRadius(double depth, double bankSlopeHorizontalToOne)
	{
	return depth + bankSlopeHorizontalToOne * Math.Pow(depth, 2);
	}
	public static double TrapezoidalArea(double depthSolution, double bottomWidth, double bankSlopeHorizontalOnONe)
	{
	return depthSolution * bottomWidth + bankSlopeHorizontalOnONe * Math.Pow(depthSolution, 2);
	}
	public static double TrapezoidalWettedPerimeter(double bottomWidth, double depthSolution, double bankSlopeHorizontalOnONe)
	{
	double hypotenuse = Math.Pow(Math.Pow(depthSolution, 2) + Math.Pow(bankSlopeHorizontalOnONe * depthSolution, 2), 0.5);
	return bottomWidth + 2 * hypotenuse;
	}
	public static double TrapezoidalTopWidth(double depthSolution, double bottomWidth, double bankSlopeHorizontalOnONe)
	{
	return bottomWidth + 2 * bankSlopeHorizontalOnONe * depthSolution;
	}
	public static double VelocityFromDepthAndFlow(double normalDepth, double bottomWidth, double bankSlopeHorizontalToOne, double flowRate)
	{
	return flowRate / TrapezoidalArea(normalDepth, bottomWidth, bankSlopeHorizontalToOne);
	}
	public static double SpecificEnergy(double depth, double velocity, double gravity)
	{
	return depth + Math.Pow(velocity, 2) / gravity;
	}