diff --git a/data/default_ammo.json b/data/default_ammo.json
index 7233f13..5b6fe29 100644
--- a/data/default_ammo.json
+++ b/data/default_ammo.json
@@ -27,7 +27,7 @@
     "EdgeDensity": 0.2,
     "InitialTemperature": 2400.0,
     "BuoyancyFactor": 0.6,
-    "EffectiveConcentration": 0.0002,
+    "EffectiveConcentration": 0.0001,
     "MaxRadius": 80.0,
     "MaxDuration": 90.0,
     "SourceStrength": 12.0,
diff --git a/src/CounterDrone.Core/Algorithms/ActiveFuelDamageModel.cs b/src/CounterDrone.Core/Algorithms/ActiveFuelDamageModel.cs
index 7aace33..f97279f 100644
--- a/src/CounterDrone.Core/Algorithms/ActiveFuelDamageModel.cs
+++ b/src/CounterDrone.Core/Algorithms/ActiveFuelDamageModel.cs
@@ -14,10 +14,7 @@ namespace CounterDrone.Core.Algorithms
             AerosolType aerosolType, float cloudDensity, float exposureTime, float deltaTime)
         {
             if (aerosolType != AerosolType.ActiveFuel) return 0f;
-            if (cloudDensity < EffectiveThreshold) return 0f;
 
-            // 伤害 = 基础速率 × e^(暴露时间 × 因子) × deltaTime
-            // 在云团中待得越久伤害指数增长
             var exponential = (float)System.Math.Exp(exposureTime * ExpFactor);
             var damage = BaseRate * exponential * deltaTime;
 
diff --git a/src/CounterDrone.Core/Algorithms/ActiveMaterialDamageModel.cs b/src/CounterDrone.Core/Algorithms/ActiveMaterialDamageModel.cs
index ec39af1..44f2049 100644
--- a/src/CounterDrone.Core/Algorithms/ActiveMaterialDamageModel.cs
+++ b/src/CounterDrone.Core/Algorithms/ActiveMaterialDamageModel.cs
@@ -15,9 +15,7 @@ namespace CounterDrone.Core.Algorithms
             AerosolType aerosolType, float cloudDensity, float exposureTime, float deltaTime)
         {
             if (aerosolType != AerosolType.ActiveMaterial) return 0f;
-            if (cloudDensity < TriggerThreshold) return 0f;
 
-            // 喷气发动机高温触发爆燃，更敏感
             if (!_triggered)
             {
                 _triggered = true;
diff --git a/src/CounterDrone.Core/Algorithms/CloudExpansionModel.cs b/src/CounterDrone.Core/Algorithms/CloudExpansionModel.cs
index 86aa15a..f53c4b2 100644
--- a/src/CounterDrone.Core/Algorithms/CloudExpansionModel.cs
+++ b/src/CounterDrone.Core/Algorithms/CloudExpansionModel.cs
@@ -17,6 +17,12 @@ namespace CounterDrone.Core.Algorithms
 
         /// <summary>Phase 1 爆轰初始半径 (m)</summary>
         public float InitialRadius => 3.3f * (float)Math.Pow(Math.Max(0.01, (float)_ammo.BurstChargeKg), 0.32f);
+        /// <summary>Phase 2 结束时的有效半径（30s 湍流膨胀）</summary>
+        public float TurbulentRadius => RadiusAt(30f);
+
+        /// <summary>Phase 2 边界时间</summary>
+        public float Phase2Duration => 30f;
+        /// <summary>湍流膨胀系数 k</summary>
         public float TurbulentExpansionK => (float)_ammo.TurbulentExpansionK;
 
         /// <summary>指定时刻湍流膨胀半径 R(t) = R₀ + k√t</summary>
@@ -64,7 +70,7 @@ namespace CounterDrone.Core.Algorithms
         /// <summary>覆盖指定距离需要的云团数量（间距=2R）</summary>
         public int RoundsNeeded(float requiredCoverage)
         {
-            float R = RadiusAt(30f);
+            float R = TurbulentRadius;
             float spacing = 2f * R;
             return Math.Max(1, (int)Math.Ceiling(requiredCoverage / spacing));
         }
diff --git a/src/CounterDrone.Core/Algorithms/DefaultAmmunition.cs b/src/CounterDrone.Core/Algorithms/DefaultAmmunition.cs
index 4dc898a..4d1dfa1 100644
--- a/src/CounterDrone.Core/Algorithms/DefaultAmmunition.cs
+++ b/src/CounterDrone.Core/Algorithms/DefaultAmmunition.cs
@@ -33,7 +33,7 @@ namespace CounterDrone.Core.Algorithms
                     InitialRadius = 5.0,
                     CoreDensity = 2.0, EdgeDensity = 0.2,
                     InitialTemperature = 2400, BuoyancyFactor = 0.6,
-                    EffectiveConcentration = 0.0002,
+                    EffectiveConcentration = 0.0001,
                     MaxRadius = 80.0, MaxDuration = 90.0,
                     SourceStrength = 12.0,
                     BurstChargeKg = 4.0, TurbulentExpansionK = 4.0,
diff --git a/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs b/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
index cfcdcff..85c5653 100644
--- a/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
+++ b/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
@@ -396,7 +396,12 @@ namespace CounterDrone.Core.Algorithms
 
             var mid = ThreatMidpoint(threat);
             var cloudModel = new CloudExpansionModel(ammo, env);
-            float expansionTime = cloudModel.TimeToReach(cloudModel.RadiusAt(30f));
+            float expansionTime = cloudModel.TimeToReach(cloudModel.TurbulentRadius);
+
+            // 密度检查：云团在膨胀时间后密度是否仍达标
+            float densityAtPassage = cloudModel.DensityAt(expansionTime);
+            if (densityAtPassage < (float)ammo.EffectiveConcentration)
+                return events; // 云团到达时已稀释失效
 
             // 编队 Y 偏移：按车道分布
             float laneSpacingZ = yLanes > 1 ? formationWidth / (yLanes - 1) : 0f;
diff --git a/src/CounterDrone.Core/Algorithms/InertGasDamageModel.cs b/src/CounterDrone.Core/Algorithms/InertGasDamageModel.cs
index 8a32095..860fadb 100644
--- a/src/CounterDrone.Core/Algorithms/InertGasDamageModel.cs
+++ b/src/CounterDrone.Core/Algorithms/InertGasDamageModel.cs
@@ -13,9 +13,6 @@ namespace CounterDrone.Core.Algorithms
             AerosolType aerosolType, float cloudDensity, float exposureTime, float deltaTime)
         {
             if (aerosolType != AerosolType.InertGas) return 0f;
-            if (cloudDensity < EffectiveThreshold) return 0f;
-
-            // 活塞发动机对惰性气体最敏感
             var sensitivity = powerType == PowerType.Piston ? 1.5f : 1.0f;
             return DamageRate * sensitivity * deltaTime;
         }
diff --git a/src/CounterDrone.Core/Simulation/SimulationEngine.cs b/src/CounterDrone.Core/Simulation/SimulationEngine.cs
index 045aee9..157b657 100644
--- a/src/CounterDrone.Core/Simulation/SimulationEngine.cs
+++ b/src/CounterDrone.Core/Simulation/SimulationEngine.cs
@@ -253,7 +253,7 @@ namespace CounterDrone.Core.Simulation
                     var dist = (float)System.Math.Sqrt(dx * dx + dy * dy + dz * dz);
                     bool inside = dist <= cloud.Dispersion.EffectiveRadius;
                     _hitLog.AppendLine($"{drone.PosX:F1},{drone.PosY:F1},{cloud.Dispersion.Center.X:F1},{cloud.Dispersion.Center.Y:F1},{dist:F1},{cloud.Dispersion.EffectiveRadius:F1},{inside}");
-                    if (inside)
+                    if (inside && cloud.Dispersion.CoreDensity >= (float)_ammoSpec.EffectiveConcentration)
                     {
                         drone.ExposureTime += scaledDt;
                         var dmg = _damageModel.CalculateDamage(drone.TargetType, drone.PowerType, cloud.AerosolType, cloud.Dispersion.CoreDensity, drone.ExposureTime, scaledDt);