Analysis


To analyse the performance of the duct, different tools are available in the Analysis-tab. On tools require an operational-point to be defined in the table on the very top. The required parameters for an operational point are the following:

The flow rate and the pressure drop - i.e. the difference between inlet and outlet pressure - are functionally connected by the ducts pressure loss coefficient. If one of these parameters is adapted, the framework will automatically adapt the others by the following sheme:

The most basic analysis-tool is the numerical analysis of each element's performance (Element analysis: Numerical). Using CTRL-A and CTRL-C, the data can be selected and copied to the clipboard to be used in other applications, such as aspreadsheet editing software. Please be aware, that Fitting-elements are also displayed in the table. Fitting-elements are used, if two connected elements show different cross-sections.

By the tab Element analysis: Graphical, a visualization of the aforementioned table can be shown. The horizontal axis represents the distance the fluid has traveled throught the duct. The read area represents the heat transfer coefficient (htc) for each element, where as the blue line represents the pressure along the duct. The green lines are the fluid (solid line) and wall (dashed line) temperatures. To identify the element at a specific location, hovver the mouse point over the location until the elements name is displayed.

To study the duct's performance under the effect of different flow rates, the Characteristic curve can be used. Here, the horizontal axis is the flow rate, where as the resulting htc and pressure drop are shown on the vertical axes. Use mouse srcolling or a double click on the axis to edit the displayed flow-rate range. To study the oeprational point of a system - i.e. a pump and a cooling sleve - pump maps can be added to the figure by a right click on the chart and selecting the menu entry Add new pump. The operational point of the system is at the intersection of the duct's and the pump's pressure curves. To remove a pump map, perform a right-click on the chart again and select the apropriate menu entry.

Studying the effects of different parameters (e.g. the elements diamters, length, ...), the Parameter sensitivity can be used. The sensitivity of a function $F$ to a parameter $\pi$ with current value $\pi_0$ is defined as $$S_\pi=\frac{\partial F}{\partial \pi}\cdot \frac{\pi_0}{F(\pi_0)}$$ There are three different taret functions to be selected from the drop-down menu at the top left:

The parameter sensitivieties are colored according to their ratio with the absolute value of the biggest sensitivity. Green coloring indicates a positive correlation (function value gets bigger if the parameter's value is increased) and red values show a negative correlation (function value gets smaller if the parameter's value is increased) .