fix: Accept GPU IDs in -gpu parameter of launch_fluent

src/ansys/fluent/core/launcher/fluent_launcher_options.json

@@ -49,16 +49,6 @@
         },
         "fluent_format": "{}"
     },
-    "gpu": {
-        "type": "bool",
-        "default": "null",
-        "fluent_required": false,
-        "fluent_map": {
-            "true": " -gpu",
-            "false": ""
-        },
-        "fluent_format": "{}"
-    },
     "scheduler": {
         "type": "str",
         "fluent_format": " -scheduler={}"

src/ansys/fluent/core/launcher/launcher.py

@@ -95,7 +95,7 @@ def launch_fluent(
     lightweight_mode: Optional[bool] = None,
     mode: Optional[Union[FluentMode, str, None]] = None,
     py: Optional[bool] = None,
-    gpu: Optional[bool] = None,
+    gpu: Union[bool, list[int], None] = None,
     cwd: Optional[str] = None,
     topy: Optional[Union[str, list]] = None,
     start_watchdog: Optional[bool] = None,
@@ -178,8 +178,13 @@ def launch_fluent(
         ``"pure-meshing"`` and ``"solver"``.
     py : bool, optional
         If True, Fluent will run in Python mode. Default is None.
-    gpu : bool, optional
-        If True, Fluent will start with GPU Solver.
+    gpu : bool or list, optional
+        This option will start Fluent with the GPU Solver. A list of GPU IDs can be
+        passed to use specific GPUs. If True is passed, the number of GPUs used will be
+        clamped to the value of ``processor_count``. Please refer to
+        *Starting the Fluent GPU Solver* section in *Fluent's User Guide* for more
+        information like how to determine the GPU IDs.
+
     cwd : str, Optional
         Working directory for the Fluent client.
     topy : bool or str, optional

src/ansys/fluent/core/launcher/launcher_utils.py

@@ -261,6 +261,11 @@ def _build_fluent_launch_args_string(**kwargs) -> str:
         )
         if parallel_options:
             launch_args_string += " " + parallel_options
+    gpu = kwargs.get("gpu")
+    if gpu is True:
+        launch_args_string += " -gpu"
+    elif isinstance(gpu, list):
+        launch_args_string += f" -gpu={','.join(map(str, gpu))}"
     return launch_args_string
 
 

tests/test_launcher.py

@@ -147,7 +147,12 @@ def test_gpu_launch_arg(helpers, monkeypatch):
     with pytest.raises(LaunchFluentError) as error:
         pyfluent.launch_fluent(gpu=True, start_timeout=0)
 
-    assert "-gpu" in str(error.value).split()
+    assert " -gpu" in str(error.value)
+
+    with pytest.raises(LaunchFluentError) as error:
+        pyfluent.launch_fluent(gpu=[1, 2, 4], start_timeout=0)
+
+    assert " -gpu=1,2,4" in str(error.value)
 
 
 def test_gpu_launch_arg_additional_arg(helpers, monkeypatch):
@@ -158,7 +163,12 @@ def test_gpu_launch_arg_additional_arg(helpers, monkeypatch):
     with pytest.raises(LaunchFluentError) as error:
         pyfluent.launch_fluent(additional_arguments="-gpu", start_timeout=0)
 
-    assert "-gpu" in str(error.value).split()
+    assert " -gpu" in str(error.value)
+
+    with pytest.raises(LaunchFluentError) as error:
+        pyfluent.launch_fluent(additional_arguments="-gpu=1,2,4", start_timeout=0)
+
+    assert " -gpu=1,2,4" in str(error.value)
 
 
 def test_kwargs():