The capillary wave and initial spreading velocity in the spreading phase of drop impacting on a glass surface are studied experimentally, while the drop photos are obtained by using a high-speed video camera, which can catch up to 9000 images per second with an exposure time of 4 µs. A wide range of impact velocities are studied by varying the fall height, showing different capillary waves. All attention is given to the capillary wave and initial spreading velocity of drop. A non-linear relation between the wavelength and the impact velocity is found experimentally. Combined with the minimum spreading radius theory, a linear relation between the initial spreading velocity and the impact velocity is acquired.

A novel temperature computation method of turbine disk is proposed according to theoretical analysis, where the coupling analysis of the outer surface in disk and fluid relative to this outer surface was carried out, instead of the segregation condition (constant wall temperature or constant wall heat flux condition). The selected correlations, numerical and experimental data of the heat transfer coefficient are presented and compared, so are the theoretical and simulated temperature profiles. The results show that: The maximum temperature deviation coefficient (φ T ) between the theoretical results and simulation data is less than 8.7% while Re Φ = 4.

In order to meet the needs of designing for high performance secondary air system in the turbine, a new turbine bite engineering rim seal of type-A and the related test rig were designed and set up. The numerical investigation and the experimental verification of the leakage characteristic of rim seal were carried out based on k -ω SST turbulence model. The key feature of the engineering rim seal of type-A, a bite type, was extracted, hence the other three kinds of rim seal named type-B, type-C and type-D were proposed. The sealing mechanism of bite rim seal was revealed from two aspects of the leakage characteristic and the seal effectiveness. The results show that: the numerical results of the k-ω SST turbulence model agree well with the experimental ones, and the maximum error is less than 4.2% in the range of this paper. The leakage of turbine bite rim seal of type-C and type-D are less than that of conventional rim seal (type-B). Compared with type-C, the radial inward shoulder structure of type-D reduces the leakage in the cavity, however, it enhances the pumping effect of the rotor. The average sealing efficiency of type-C and type-D are increased by 8.9% and 8.82% compared with that of conventional rim seal of type-B, respectively. The effects of entrainment and diffusion of the vortex in the sealing channel are one of the important reasons for the ingestion. There are two kinds of vortex structure named recirculation zone vortex (RZV) and rotationally induced vortex (RIV). The RZV will be rapidly replaced by the RIV with the rotation speed increasing at a low flow rate of the hot gas. However, the RZV will be relatively stable while the hot gas mass flow rate is increased.