Flow in a Turbine Cascade: Part 2—Measurement of Flow Trajectories by Ethylene Detection

In Part 1 of this paper, measurements of total pressure loss were described at an axial location 40 percent of the axial chord downstream of the trailing edge of a turbine cascade. These results revealed regions of high loss near midspan away from the walls and in the bulk of the flow. In this second part, the origins of fluid in these regions are traced using an ethylene detection technique. Ethylene injection near the blade leading edges and gas sampling downstream and near the blade trailing edges gives information about flow trajectories and mixing through the cascade. Details of the flame ionization detection system used to measure the ethylene concentrations are discussed.