The Performance of Slotted Blades in Cascade

A precise solution of the problem of determining a two-dimensional potential flow of inocomplessible fluid around arbitrary shaped slotted blades in cascade was obtained by conformal mapping. This solution facilitates precise evaluation of the extrmely complicated calculations around the slot even if the slat and the main aerofoil are approximated close to each other. Utilization of a modified Milne-Thomson's circle theorem together with Milne-Thomson's circle theorem, as a means of analysis, gives simple expressions of mapping function and complex potential function, suitable for electronic computer calculations. Wind tunnel tests, with comparison between slotted and unslotted cascades, were also conducted. Slight slot effect was obtained in both outer regions of flow inlet angle. However, in the middle region of inlet angle, slot effect was insufficient due to the divergent shape of slot employed.