| The novel feature of the co-turboshaft engine is a rotating compressor casing, which co-rotates with the gas generator spool, hence, the name "co-turboshaft." This casing derives power from the compressor air stream and this power is transmitted to the output shaft, and is combined with the power turbine output in an epicyclic gear box. As load increases and output shaft speed decreases, the effective gas generator speed increases, with no increase in rotor speed, and the power output rises. This produces steeper torque-speed characteristics than conventional two-shaft gas turbine engines.; A study of the effects of the design parameters on the performance of the co-turboshaft engine is carried out. The basis of selection of these parameters to achieve the best performance, both mechanically and thermodynamically, is presented.; The thesis examines the potential of the co-turboshaft engine for use in vehicular applications. The basic characteristics of such an engine are being presented for assessment as a vehicle power plant. The co-turboshaft engine is compared to a conventional power plant, to assess the comparative performance of each. A comparison of the performance of a specific co-turboshaft engine and of a conventional engine, provided with sophisticated control systems, is also carried out.; A simulation program, utilizing well developed hybrid computer techniques, has been built for a co-turboshaft engine. It provides a very flexible computer model that can be used and adapted to a wide variety of further studies. It became thus a simple task to extend the study to a regenerative co-turboshaft engine and to incorporate components of different characteristics into the model.; Results of the hybrid computer model, along with the analytical studies presented in this thesis, have provided a vast amount of insight into the "co-turboshaft" engine. |
