From 1dc9cd0031ec9d97dab318d3ec4e531139d140c3 Mon Sep 17 00:00:00 2001
From: "p.vanderwilt" <p.van.der.wilt@brabantsedelta.nl>
Date: Tue, 14 Oct 2025 12:48:43 +0200
Subject: [PATCH] Add dispersion constraint

---
 src/specificClass.js | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/specificClass.js b/src/specificClass.js
index eb42032..3aeef2f 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -266,15 +266,16 @@ class Reactor_PFR extends Reactor {
    * @param {object} input - Input object (msg) containing payload with dispersion value [m2 d-1].
    */
   set setDispersion(input) {
-    this.D = input.payload;
+    this.D = this._constrainDispersion(input.payload);
   }
 
   updateState(newTime) {
     super.updateState(newTime);
-    let Pe_local = this.d_x*math.sum(this.Fs)/(this.D*this.A)
+    // let Pe_local = this.d_x*math.sum(this.Fs)/(this.D*this.A)
+    this.D = this._constrainDispersion(this.D);
     let Co_D = this.D*this.timeStep/(this.d_x*this.d_x);
 
-    (Pe_local >= 2) && this.logger.warn(`Local Péclet number (${Pe_local}) is too high! Increase reactor resolution.`);
+    // (Pe_local >= 2) && this.logger.warn(`Local Péclet number (${Pe_local}) is too high! Increase reactor resolution.`);
     (Co_D >= 0.5) && this.logger.warn(`Courant number (${Co_D}) is too high! Reduce time step size.`);
 
     if(DEBUG) {
@@ -402,6 +403,15 @@ class Reactor_PFR extends Reactor {
     D2.forEach((row, i) => i < BC_PADDING || i >= this.n_x+BC_PADDING ? row.fill(0) : row);
     return D2;
   }
+
+  _constrainDispersion(D) {
+    const Dmin = math.sum(this.Fs) * this.d_x / (1.999 * this.A);
+    if (D < Dmin) {
+      this.logger.warn(`Local Péclet number too high! Constraining given dispersion (${D}) to minimal value (${Dmin}).`);
+      return Dmin;
+    }
+    return D;
+  }
 }
 
 module.exports = { Reactor_CSTR, Reactor_PFR };