Controlling CFD runs ==================== Starting CFD runs ----------------- CFD runs can be started in **CFturbo BLADERUNNER** from any level in the **workspace tree** by selecting **Start** from the context menu. The CFD runs are then carried out sequentially for all objects on the level below. Selecting **Start** on the **performance curve** level, for example, initiates CFD runs for all **operating points** of this **performance curve**. For a quick overview, it is sometimes useful to start simulations for some individual **operating points**, the design point, one point to the left and one point to the right of it, using the context menu of the individual **operating point**. Whether **Steady**, **Transient**, or **Steady and transient** flow simulations are started depends on the **Run type** setting of the respective **performance curve**. Information about the status of a flow simulation is provided by the two columns **S** for **Steady** and **T** for **Transient** runs in the **workspace bar** to the right of the columns **E** for geometry export and **M** for meshing. .. figure:: images/start_cfd2.png :align: center Starting **Steady and transient** flow simulations for a whole **performance curve** When starting one or more flow simulations **CFturbo BLADERUNNER** - first saves the **workspace**, eventually asking for a file name - |waiting| queues the **operating points** to be computed in the order in which they were selected - |license| checks whether a **Simerics MP/MP+** license is available - |running| starts the computation of the first **operating point** in the queue .. |waiting| image:: images/status_waiting.gif :align: middle :scale: 25 .. |license| image:: images/checking_license.gif :align: middle :scale: 30 .. |running| image:: images/status_running.gif :align: middle :scale: 33 With the **Steady and transient** option, two series of CFD runs can be started at once, first a series of **Steady** simulations followed by a series of **Transient** simulations, with or without initialization by the results of the **Steady** simulations. If **Intelligent** is selected as the **RUN SCHEME** for the **Steady** simulations, the flow simulation for a new **operating point** is initialized with the result of a neighboring **operating point**. With the **Middle** setting, the calculation of the middle point of the **performance curve** is started, which usually corresponds to the **design point** of the turbomachine. .. figure:: images/steadyTransientMiddle_steps.png :align: center Processing steps for **Steady and transient** CFD runs using the option **Intelligent - Middle** If no license for **Simerics MP/MP+** is available for a CFD run a red exclamation mark appears on the icon of the corresponding **operating point**, a **tooltip** indicates that the **Simulation was not successful**, and the error message **License request failed** appears in the **log window**. .. figure:: images/nolicense_error1.png :align: center .. figure:: images/nolicense_error2.png :align: center Error messages in case of **Simerics MP/MP+** license unavailability Stopping CFD runs ----------------- Stopping flow simulations is just as easy as starting them. Selecting **Stop** from the context menu of any object in the **workspace tree** stops the running flow simulation and all pending ones below this level. Stopping flow simulations for example on the **performance curve** level stops the flow simulations of all **operating points** belonging to this **performance curve** even if they were started one by one for particular **operating points**. Depending on the size of the mesh it may take a while until all data is written to the **.sres** result file. .. image:: images/stop_cfd2.png :align: center Showing/hiding and checking the status of CFD results ----------------------------------------------------- Once a flow simulation has been successfully started and is running, initial data is available and can be monitored. The **operating point** and all levels above such as the respective performance curve, variant ans so on then show a **checkbox** in the **workspace tree** that can be used to enable or disable the visibility of **performance curves** and curves of residuals, in **CFturbo BLADERUNNER** referred to as **convergence plots**. Results are obviously also available for all completed flow simulations. The status in column **S** (**Steady**) or **T** (**Transient**) provides information about the quality of these results: - ✓ - convergence criteria met - ● - convergence criteria **not** met, but maximum number of iterations reached - ○ - convergence criteria **not** met, maximum number of iterations **not** reached In the latter case, the flow simulation was probably terminated by the user. **CFD results** may easily be **outdated** in case the user changes any of the following values after the **performance curve** has been computed: **ROTATIONAL SPEED**, **FLOW BOUNDARY CONDITIONS** (value or type), **FLUID PROPERTIES**, **Cavitation** or the **Gravity** vector under **SOLVER SETTINGS**, or the **NUMERIC SCHEME**. Then the symbols above change to **orange** color. If **Simerics MP/MP+ .sres** simulation result files are no longer available, for example if they have been deleted in order to generate a ZIP file of the **workspace** with minimum size, a small **x** is displayed next to the respective simulation status symbols. .. figure:: images/results_available2.png :align: center **Visibility** and **status** of CFD results If the user changes the **maximum number of iterations** or the **convergence criteria** after the results have been calculated, these results are **not outdated** but may not meet the new maximum number of iterations or the new convergence criteria. Their status will then continue to be displayed in gray, but the symbols may shift. .. figure:: images/status_change.png :align: center Shift of **status symbols** when changing iteration and/or convergence criteria Locking/unlocking CFD results ----------------------------- When examining different CFturbo designs in CFturbo BLADERUNNER, it is advantageous to protect them from accidental deletion or from recalculation of the CFD results, which often took a considerable amount of time to generate. For each element of the **workspace tree**, the **Lock** option is therefore available in the context menu, which can be used to protect entire variants, studies, or projects, as well as individual performance curves and operating points from being changed or deleted. The respective element and the elements in its subordinate branches are then marked with **small filled orange lock symbols**. It is irrelevant whether the CFD results of these elements are marked visible or not. .. image:: images/lock_variant.png :align: center Options such as **Start** or **Remove** are then grayed out, while the CFD results of an operating point can still be analyzed in **Simerics MP/MP+** via **Open steady results** and/or **Open transient results**, and the directory with the associated files remains accessible via **Open directory**. Individual elements can be unlocked using the **Unlock** option in the context menu, for example, to recalculate a single **operating point**. .. image:: images/unlock_operatingpoint.png :align: center If only parts of the subordinate tree structure of an element are locked, e.g. only individual variants of a study, an **empty orange lock symbol** appears. .. image:: images/lock_unlock_study.png :align: center In this case the **Lock** and **Unlock** options are both available in the context menu of this element to lock or unlock the entire structure.