String selectedTag = "";

if (java.util.Arrays.asList(model.component().tags()).contains("comp1")
    && java.util.Arrays.asList(model.sol().tags()).contains("nrel_sol")) {
    if (java.util.Arrays.asList(
            model.component("comp1").selection().tags()
        ).contains("nrel_air")) {
        selectedTag = model.tag();
    }
}

if (selectedTag.length() == 0) {
    java.util.ArrayList<String> candidates =
        new java.util.ArrayList<String>();

    for (String tag : com.comsol.model.util.ModelUtil.tags()) {
        com.comsol.model.Model candidate =
            com.comsol.model.util.ModelUtil.model(tag);

        if (!java.util.Arrays.asList(
                candidate.component().tags()
            ).contains("comp1")) {
            continue;
        }

        if (java.util.Arrays.asList(candidate.sol().tags())
                .contains("nrel_sol")
            && java.util.Arrays.asList(
                candidate.component("comp1").selection().tags()
            ).contains("nrel_air")) {
            candidates.add(tag);
        }
    }

    if (candidates.size() != 1) {
        throw new IllegalStateException(
            "无法唯一定位 NREL 流场模型，候选：" + candidates
        );
    }
    selectedTag = candidates.get(0);
}

model = com.comsol.model.util.ModelUtil.model(selectedTag);

int[] airDomains =
    model.component("comp1").selection("nrel_air").entities(3);

if (airDomains.length == 0) {
    throw new IllegalStateException("空气域选择为空。");
}

int[] wallBoundaries = new int[0];
if (java.util.Arrays.asList(
        model.component("comp1").selection().tags()
    ).contains("nrel_blade_wall")) {
    wallBoundaries =
        model.component("comp1").selection("nrel_blade_wall").entities(2);
}

String dataTag = "nrel_cloud_solution";

if (!java.util.Arrays.asList(
        model.result().dataset().tags()
    ).contains(dataTag)) {
    model.result().dataset().create(dataTag, "Solution");
} else if (!"Solution".equals(
        model.result().dataset(dataTag).getType())) {
    throw new IllegalStateException("已有流场数据集类型不匹配。");
}

model.result().dataset(dataTag).set("solution", "nrel_sol");
model.result().dataset(dataTag).set("comp", "comp1");
model.result().dataset(dataTag).selection().geom("geom1", 3);
model.result().dataset(dataTag).selection().set(airDomains);

// Q = 0.5*(旋转张量平方范数 - 应变率张量平方范数)
// 直接使用速度空间导数，不依赖物理场专用 Q 变量名称。
String qExpr =
    "-0.5*(d(u,x)^2+d(v,y)^2+d(w,z)^2"
    + "+2*d(u,y)*d(v,x)"
    + "+2*d(u,z)*d(w,x)"
    + "+2*d(v,z)*d(w,y))";

String[] plotTags = new String[]{
    "nrel_vortex_q1",
    "nrel_vortex_q5",
    "nrel_vortex_q20"
};

String[] thresholds = new String[]{
    "1[1/s^2]", "5[1/s^2]", "20[1/s^2]"
};

for (int i = 0; i < plotTags.length; i++) {
    String tag = plotTags[i];

    if (!java.util.Arrays.asList(model.result().tags()).contains(tag)) {
        model.result().create(tag, "PlotGroup3D");
    } else if (!"PlotGroup3D".equals(model.result(tag).getType())) {
        throw new IllegalStateException("同名节点不是三维绘图组：" + tag);
    }

    model.result(tag).label("涡结构：Q=" + thresholds[i]);
    model.result(tag).set("data", dataTag);

    if (!java.util.Arrays.asList(
            model.result(tag).feature().tags()
        ).contains("iso1")) {
        model.result(tag).create("iso1", "Isosurface");
    } else if (!"Isosurface".equals(
            model.result(tag).feature("iso1").getType())) {
        throw new IllegalStateException("iso1 类型不匹配：" + tag);
    }

    model.result(tag).feature("iso1").set("data", dataTag);
    model.result(tag).feature("iso1").set("expr", qExpr);
    model.result(tag).feature("iso1").set("unit", "1/s^2");
    model.result(tag).feature("iso1").set("descr", "Q 判据涡结构");
    model.result(tag).feature("iso1").set("levelmethod", "levels");
    model.result(tag).feature("iso1")
        .set("levels", new String[]{thresholds[i]});
    model.result(tag).feature("iso1").set("coloring", "uniform");
    model.result(tag).feature("iso1").set("color", "cyan");

    if (!java.util.Arrays.asList(
            model.result(tag).feature("iso1").feature().tags()
        ).contains("sel1")) {
        model.result(tag).feature("iso1").create("sel1", "Selection");
    }
    model.result(tag).feature("iso1").feature("sel1")
        .selection().geom("geom1", 3);
    model.result(tag).feature("iso1").feature("sel1")
        .selection().set(airDomains);

    // 叠加叶轮壁面压力，帮助辨认涡结构与叶片的位置关系。
    if (wallBoundaries.length > 0) {
        if (!java.util.Arrays.asList(
                model.result(tag).feature().tags()
            ).contains("blade1")) {
            model.result(tag).create("blade1", "Surface");
        } else if (!"Surface".equals(
                model.result(tag).feature("blade1").getType())) {
            throw new IllegalStateException("blade1 类型不匹配：" + tag);
        }

        model.result(tag).feature("blade1").set("data", dataTag);
        model.result(tag).feature("blade1").set("expr", "p");
        model.result(tag).feature("blade1").set("unit", "Pa");
        model.result(tag).feature("blade1").set("descr", "叶轮壁面压力");

        if (!java.util.Arrays.asList(
                model.result(tag).feature("blade1").feature().tags()
            ).contains("sel1")) {
            model.result(tag).feature("blade1").create("sel1", "Selection");
        }

        model.result(tag).feature("blade1").feature("sel1")
            .selection().geom("geom1", 2);
        model.result(tag).feature("blade1").feature("sel1")
            .selection().set(wallBoundaries);
    }
}

// 先显示最低阈值，另外两张图按需点击绘制。
model.result("nrel_vortex_q1").run();

System.out.println("已添加 Q=1、5、20 [1/s²] 三个涡结构绘图组。");
System.out.println("青色表示 Q 等值面；叶轮表面颜色表示压力。");
System.out.println("阈值越高，一般只保留更强的局部涡结构。");
System.out.println("若只有叶轮而没有等值面，该阈值可能不在当前 Q 场范围内。");
System.out.println("当前图来自粗网格定常冻结转子解，不能代表瞬态尾涡演化。");
System.out.println("本轮未启动求解，未修改几何或网格。");