feat(ui): add Mode 1/2/3 Reynolds type selector to Solve panel

Expose XFOIL's ReType (constant Re, fixed Re√CL, fixed Re·CL) in the
UI as a three-button toggle under the Reynolds Number input. Mode 1 is
the default. Threads re_type through WASM bindings, sweep engine, and
airfoil store.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aeronauty

crates/rustfoil-wasm/src/lib.rs

@@ -925,13 +925,22 @@ fn bl_error(message: impl Into<String>) -> BLDistribution {
     }
 }
 
+fn re_type_from_int(v: u8) -> rustfoil_xfoil::config::ReType {
+    match v {
+        2 => rustfoil_xfoil::config::ReType::Type2,
+        3 => rustfoil_xfoil::config::ReType::Type3,
+        _ => rustfoil_xfoil::config::ReType::Type1,
+    }
+}
+
 fn faithful_snapshot(
     coords: &[f64],
     alpha_deg: f64,
     reynolds: f64,
     mach: f64,
     ncrit: f64,
     max_iterations: usize,
+    re_type: u8,
 ) -> Result<FaithfulSnapshot, String> {
     if coords.len() < 6 || coords.len() % 2 != 0 {
         return Err("Invalid coordinates: need at least 3 points (6 values)".to_string());
@@ -996,6 +1005,7 @@ fn faithful_snapshot(
         mach,
         ncrit,
         max_iterations,
+        re_type: re_type_from_int(re_type),
         ..Default::default()
     };
     let oper_result = solve_operating_point_from_state(&mut state, &factorized, &options)
@@ -1141,8 +1151,9 @@ pub fn analyze_airfoil_faithful(
     mach: f64,
     ncrit: f64,
     max_iterations: usize,
+    re_type: u8,
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, re_type) {
         Ok(snapshot) => snapshot.result,
         Err(message) => analysis_error(message),
     };
@@ -1158,7 +1169,7 @@ pub fn get_bl_distribution_faithful(
     ncrit: f64,
     max_iterations: usize,
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
         Ok(snapshot) => rows_to_bl_distribution(
             &snapshot.upper_rows,
             &snapshot.lower_rows,
@@ -1264,7 +1275,7 @@ pub fn get_bl_visualization_faithful(
     ncrit: f64,
     max_iterations: usize,
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
         Ok(snapshot) => build_bl_visualization(&snapshot),
         Err(message) => bl_vis_error(message),
     };
@@ -1442,7 +1453,7 @@ pub fn compute_streamlines_faithful(
     seed_count: u32,
     bounds: &[f64],
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
         Ok(snapshot) => {
             if bounds.len() != 4 {
                 StreamlineResult {
@@ -1585,7 +1596,7 @@ pub fn compute_dividing_streamline_faithful(
     max_iterations: usize,
     bounds: &[f64],
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
         Ok(snapshot) => {
             if bounds.len() != 4 {
                 DividingStreamlineResult {
@@ -1809,7 +1820,7 @@ pub fn compute_psi_grid_faithful(
     bounds: &[f64],
     resolution: &[u32],
 ) -> JsValue {
-    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+    let result = match faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
         Ok(snapshot) => {
             if bounds.len() != 4 {
                 PsiGridResult {
@@ -1952,7 +1963,7 @@ impl WasmSmokeSystem {
         ncrit: f64,
         max_iterations: usize,
     ) {
-        if let Ok(snapshot) = faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations) {
+        if let Ok(snapshot) = faithful_snapshot(coords, alpha_deg, reynolds, mach, ncrit, max_iterations, 1) {
             let field = FaithfulFlowField::from_snapshot(&snapshot, alpha_deg);
             self.coords = field.nodes.clone();
             self.gamma = field.gamma.clone();
@@ -3503,7 +3514,7 @@ mod tests {
         let paneled_flat = repanel_xfoil(&buffer_flat, 160);
         let alpha_deg = 15.0;
 
-        let snapshot = faithful_snapshot(&paneled_flat, alpha_deg, 1.0e6, 0.0, 9.0, 100)
+        let snapshot = faithful_snapshot(&paneled_flat, alpha_deg, 1.0e6, 0.0, 9.0, 100, 1)
             .expect("faithful snapshot should solve");
         let field = FaithfulFlowField::from_snapshot(&snapshot, alpha_deg);
         let options = StreamlineOptions {

flexfoil-ui/src/components/panels/SolvePanel.tsx

@@ -14,7 +14,7 @@ import { useCaseLogStore } from '../../stores/caseLogStore';
 import { analyzeAirfoil, analyzeAirfoilInviscid, isWasmReady, type AnalysisResult } from '../../lib/wasm';
 import { useSolverJobStore } from '../../stores/solverJobStore';
 import { runSweep, type SweepConfig, type SweepRunData } from '../../lib/sweepEngine';
-import type { PolarPoint, SweepAxis, SweepParam } from '../../types';
+import type { PolarPoint, SweepAxis, SweepParam, ReType } from '../../types';
 import type { RunInsert } from '../../lib/storageBackend';
 import { parseSweepValues, formatSweepValues } from '../../lib/parseSweepValues';
 
@@ -61,6 +61,8 @@ export function SolvePanel() {
     setNcrit,
     setMaxIterations,
     setSolverMode,
+    reType,
+    setReType,
     upsertPolar,
     clearAllPolars,
   } = useAirfoilStore();
@@ -178,10 +180,10 @@ export function SolvePanel() {
 
   const runSolver = useCallback((coords: { x: number; y: number }[], alpha: number) => {
     if (isViscous) {
-      return analyzeAirfoil(coords, alpha, reynolds, mach, ncrit, maxIterations);
+      return analyzeAirfoil(coords, alpha, reynolds, mach, ncrit, maxIterations, reType);
     }
     return analyzeAirfoilInviscid(coords, alpha);
-  }, [isViscous, reynolds, mach, ncrit, maxIterations]);
+  }, [isViscous, reynolds, mach, ncrit, maxIterations, reType]);
 
   /** Cache key uses Re=0/Mach=0/Ncrit=0/maxIter=0 for inviscid to separate caches. */
   const cacheRe = isViscous ? reynolds : 0;
@@ -761,6 +763,7 @@ export function SolvePanel() {
         ncrit,
         maxIterations,
         solverMode,
+        reType,
         baseCoordinates: base,
         panels,
         flaps: geometryDesign.flaps,
@@ -828,7 +831,7 @@ export function SolvePanel() {
       sweepAbortRef.current = null;
     }
   }, [panels, sweepPrimary, sweepSecondary, displayAlpha, reynolds, mach, ncrit,
-      maxIterations, solverMode, geometryDesign.flaps, name, isViscous, upsertPolar, addRun, addRunBatch,
+      maxIterations, solverMode, reType, geometryDesign.flaps, name, isViscous, upsertPolar, addRun, addRunBatch,
       jobDispatch, jobComplete, jobUpdate]);
 
   // --------------- derived ---------------
@@ -892,6 +895,31 @@ export function SolvePanel() {
           </div>
         )}
 
+        {isViscous && (
+          <div className="form-group">
+            <div className="form-label">Mode</div>
+            <div style={{ display: 'flex', gap: '4px', marginBottom: '4px' }}>
+              {([1, 2, 3] as ReType[]).map((m) => (
+                <button
+                  key={m}
+                  onClick={() => setReType(m)}
+                  className={reType === m ? 'active' : ''}
+                  style={{ flex: 1 }}
+                >
+                  {m}
+                </button>
+              ))}
+            </div>
+            <div style={{ fontSize: '10px', color: 'var(--text-muted)', marginTop: '2px' }}>
+              {reType === 1
+                ? 'Constant Re'
+                : reType === 2
+                  ? 'Fixed Re·√CL (variable speed)'
+                  : 'Fixed Re·CL (propeller/turbo)'}
+            </div>
+          </div>
+        )}
+
         {isViscous && (
           <div className="form-group">
             <button

flexfoil-ui/src/lib/sweepEngine.ts

@@ -11,6 +11,7 @@ import type {
   FlapDefinition,
   PolarPoint,
   SolverMode,
+  ReType,
   SweepAxis,
   SweepParam,
 } from '../types';
@@ -27,6 +28,7 @@ export interface SweepConfig {
   ncrit: number;
   maxIterations: number;
   solverMode: SolverMode;
+  reType: ReType;
   baseCoordinates: AirfoilPoint[];
   panels: AirfoilPoint[];
   flaps: FlapDefinition[];
@@ -234,7 +236,7 @@ export async function runSweep(
       // Solve
       try {
         const res = isViscous
-          ? analyzeAirfoil(panels, alpha, reynolds, mach, ncrit, config.maxIterations)
+          ? analyzeAirfoil(panels, alpha, reynolds, mach, ncrit, config.maxIterations, config.reType)
           : analyzeAirfoilInviscid(panels, alpha);
 
         if (res.success) {

flexfoil-ui/src/lib/wasm.ts

@@ -320,20 +320,22 @@ export function analyzeAirfoil(
     reynolds: number = 1e6,
     mach: number = 0,
     ncrit: number = 9,
-    maxIterations: number = 100
+    maxIterations: number = 100,
+    reType: number = 1,
 ): AnalysisResult {
     if (!initialized) {
         throw new Error('WASM not initialized. Call initWasm() first.');
     }
-    
+
     const coordsFlat = pointsToFlat(coordinates);
     return analyze_airfoil_faithful(
         coordsFlat,
         alphaDeg,
         reynolds,
         mach,
         ncrit,
-        maxIterations
+        maxIterations,
+        reType,
     ) as AnalysisResult;
 }
 

flexfoil-ui/src/stores/airfoilStore.ts

@@ -11,6 +11,7 @@ import type {
   AirfoilPoint, 
   ControlMode, 
   SolverMode,
+  ReType,
   BezierHandle, 
   BSplineControlPoint,
   SpacingKnot,
@@ -143,7 +144,8 @@ interface AirfoilStore extends AirfoilState {
   setNcrit: (ncrit: number) => void;
   setMaxIterations: (maxIterations: number) => void;
   setSolverMode: (mode: SolverMode) => void;
-  
+  setReType: (reType: ReType) => void;
+
   // Point manipulation (legacy, kept for compatibility)
   updatePoint: (index: number, point: AirfoilPoint) => void;
   addPoint: (index: number, point: AirfoilPoint) => void;
@@ -288,6 +290,7 @@ export const useAirfoilStore = create<AirfoilStore>()(
       ncrit: 9,
       maxIterations: 100,
       solverMode: 'viscous',
+      reType: 1 as ReType,
       polarData: [],
       spacingPanelMode: 'simple',  // Default to simple curvature-based
       sspInterpolation: 'linear',  // Default to linear (Mark Drela's original)
@@ -316,6 +319,7 @@ export const useAirfoilStore = create<AirfoilStore>()(
       setNcrit: (ncrit) => set({ ncrit: Math.max(1, Math.min(14, ncrit)) }),
       setMaxIterations: (maxIterations) => set({ maxIterations: Math.max(10, Math.min(500, maxIterations)) }),
       setSolverMode: (solverMode) => set({ solverMode }),
+      setReType: (reType) => set({ reType }),
 
       updatePoint: (index, point) => set((state) => {
         const newCoords = [...state.coordinates];

flexfoil-ui/src/types/index.ts

@@ -19,6 +19,8 @@ export interface AirfoilPoint extends Point {
 /** Control modes for airfoil manipulation */
 export type ControlMode = 'parameters' | 'camber-spline' | 'thickness-spline' | 'inverse-design' | 'geometry-design';
 export type SolverMode = 'viscous' | 'inviscid';
+/** XFOIL Reynolds number constraint type (1=constant Re, 2=fixed Re√CL, 3=fixed Re·CL) */
+export type ReType = 1 | 2 | 3;
 export type RunMode = 'alpha' | 'cl';
 export type AxisVariable = 'alpha' | 'cl' | 'cd' | 'cm' | 'ld'
   | 'reynolds' | 'mach' | 'ncrit' | 'flapDeflection' | 'flapHingeX';
@@ -157,6 +159,8 @@ export interface AirfoilState {
   maxIterations: number;
   /** Active solver mode */
   solverMode: SolverMode;
+  /** Reynolds number constraint type (Mode 1/2/3) */
+  reType: ReType;
   /** Polar sweep data — multiple series keyed by solver config */
   polarData: PolarSeries[];
   /** Spacing panel mode: simple (curvature-based) or advanced (SSP) */