The horizontal axis represents x star, ranging from zero point two to one, while the vertical axis represents the variable ranging from zero point eight to one point three. The graph displays two data sets using dashed lines: a red dashed line represents data for eight modules, and a blue dashed line represents data for four modules. Each data line includes star-shaped markers indicating specific data points. A legend in the upper left corner identifies the colour and symbol used for each module configuration.
Performance index η estimated for the eight- and four-finned modules