RESUMEN
Thermal barrier coating (TBC) systems are widely adopted in gas turbine blades to improve the thermal efficiency of gas turbine engines. However, TBC failure will happen due to the thermal stress between the different layers of the TBC systems. The traditional two-layer theoretical model only considers TGO (thermally grown oxide) and a substrate in the inner cooling hole with the surface uncoated, which results in poor prediction of the deformations of the TBC systems. It should be mentioned that the effect of TBC is very important because the thickness of TBC is much larger than the TGO thickness. In this study, a new three-layer theoretical model was derived, which is composed of the cylindrical TGO and TBC mounted in the substrate with a circular hole, and the stress and strain of TGO near the cooling hole under the condition of the thermal cycles were calculated. The high temperature characteristics of TGO and the substrate including the high temperature strength and growth ratio were from the experiments. The results show that the strain of the developed three-layer model is irrelevant with increasing number of cycles, which indicates that TBC in the cooling hole significantly inhibits the deformation of TGO near the cooling hole. Therefore, aimed at confirming the feasibility of the three-layer theoretical model, the finite element analysis with coating in the cooling hole and on the surface was carried out with a three-layer axisymmetric model, which proves that the 3-layer theoretical model can predict the deformation trend near the cooling hole.
RESUMEN
The individual dose caused by airborne effluents varies with the height of the chimney. In order to reduce the individual dose caused by uranium enrichment facilities, the height of the chimney is optimized, and considering the impact of radioactive effluents within 5 km of the site, the Cairdos program is used to simulate and predict the long-term atmospheric diffusion factors and individual dose distribution.The results showed that 234U had a greater impact on individual dose contribution, and the long-term dispersion factor and the maximum individualdose appeared in the southeast-east (ESE) direction. The individual dose caused by 10 m, 30 m and 60 m chimneys was 6.78, 3.41 and 1.60 times that of the 80 m chimney, respectively. Therefore, increasing the height of the chimney can effectively reduce the individual dose. The peak value of the individual dose caused by the 150 m and 200 m chimneys was 0.39 and 0.32 times that of the 80 m chimney, respectively. Therefore, When the chimney height is higher than 80m, the extra high chimney can reduce the individual dose, but the decrease of the individual dose is significantly less than the increase of chimney height.