added valves display

Components/Nozzleflow.cs

@@ -0,0 +1,46 @@
+using System;
+
+namespace FluidSim.Components
+{
+    public static class NozzleFlow
+    {
+        /// <summary>
+        /// Computes the nozzle‑exit primitive state and mass flow rate from a
+        /// volume to a pipe, using isentropic relations. Follows ensim4's flow() logic.
+        /// </summary>
+        public static void Compute(double Pt_high, double Tt_high,
+                                   double P_low, double gamma, double R, double area,
+                                   out double rhoExit, out double uExit,
+                                   out double pExit, out double mdot)
+        {
+            double gm1 = gamma - 1.0;
+            double Pt_over_Ps = Pt_high / P_low;
+
+            // Mach number (subsonic, clamped to 1)
+            double M = Math.Sqrt(Math.Max(0.0,
+                (2.0 / gm1) * (Math.Pow(Pt_over_Ps, gm1 / gamma) - 1.0)));
+            if (M > 1.0) M = 1.0;
+
+            double T_star = Tt_high / (1.0 + 0.5 * gm1 * M * M);
+            double a_star = Math.Sqrt(gamma * R * T_star);
+            double u_star = M * a_star;
+            pExit = Pt_high * Math.Pow(1.0 + 0.5 * gm1 * M * M, -gamma / gm1);
+            rhoExit = pExit / (R * T_star);
+            uExit = u_star;   // positive away from high‑pressure side
+            mdot = rhoExit * uExit * area;
+        }
+
+        /// <summary>
+        /// Ambient cell for non‑reflecting open end (ensim4 calc_ambient_cell).
+        /// </summary>
+        public static void ComputeAmbientCell(double rhoInt, double uInt, double pInt,
+                                               double pAmbient, double gamma,
+                                               out double rhoAmb, out double uAmb,
+                                               out double pAmb)
+        {
+            pAmb = pAmbient;
+            uAmb = uInt;
+            rhoAmb = rhoInt * Math.Pow(pAmb / pInt, 1.0 / gamma);
+        }
+    }
+}