Study of aerodynamic performance of built-in variable wavelength traveling wave turbine

Turbines, as power sources for power generation, ships, etc. are capable of absorbing energy from high-temperature and high-pressure gas, converting thermal energy into mechanical energy. We propose a built-in variable wavelength traveling wave turbine that establishes a traveling wave mechanism in the rectangular flow channel. This device has the same function as a conventional turbine, extracting energy from incoming high-pressure gas, but it operates in a completely different way from axial flow and centripetal types. Numerical simulation is adopted to investigate the energy absorption characteristics and flow mechanism of the variable wavelength traveling wave turbine of two wave numbers. The traveling wave turbine is simplified to a two-dimensional traveling wave plate with analytical functions to control the motion parameters. The results show that influenced by variable wavelength, the motion waveform forms expansion type, equal wavelength type and contraction type. The curve of energy absorption rate of traveling wave turbine shows first increase and then decrease with the highest efficiency reaching 89.71%. The mass flow coefficients under two wave numbers correspond to the efficiency curves with approximately the same trend. There is the obvious distinction between pressure regions divided by the moving traveling wave plate, indicating that fluid energy is mainly transferred to traveling wave plate. The velocity varies prominently in X direction near the leading edge and trailing edge of the plate. Interestingly, as the variable wavelength changes, the vortex direction alters where the first formed vortex sheet shed the trailing part of the traveling wave plate. The area of vortex sheet varies significantly.