دانلود رایگان مقاله آنالیز حرارتی حفره ایجاد شده در پوشش سرامیکی برای پیستون موتور دیزل

Abstract

This paper deals with the steady state thermal analysis of diesel engine piston coated with ceramic coating having holes on its surface. Temperature distribution on the piston's top surface and substrate surface is investigated by using finite element based software called Ansys. Yttria-stabilized Zirconia is used as ceramic coating applied on Al–Si piston crown. The 2 thickness of ceramic top coating is about 0.4 mm and for NiCrAl bond coat it is taken to be 0.1 mm. Temperature distribution is investigated by choosing various radiuses of holes created on the ceramic coating surface about 1.5 mm, 2 mm and 2.5 mm. From the results it is observed that the top surface (coated surface) temperature is increasing with increase the radius of the holes. Maximum temperature of coated surface is occurs for highest hole radius of about 2.5 mm. Compared with coating have no hole, a significant increase in the pistons top surface temperature occurs with coating having holes. Although, the substrate temperature is decreasing with increase the radius of the holes.

8. Conclusion

From the above analysis, it is clear that TBC help to increase the temperature of the piston. The maximum temperature for top coating surface and substrate surface occurs at the center of the piston and at the piston's rim area. The temperature is increased from the bottom of the piston to the head. Coated piston has a significantly higher temperature than uncoated piston and after that the top surface temperature is increased by increasing the radius of the holes. The corresponding top surface maximum temperature for the uncoated, coated piston, coating with 1.5 mm radius hole, 2 mm radius hole and 2.5 mm radius hole is 291.32 °C, 362.5 °C, 402.93 °C, 444.54 °C and 540.96 °C respectively. The Maximum temperature on the top surface is observed for coating having hole of 2.5 mm radius which is about 540.96 °C and 85.69% and 49.23% higher compared to uncoated and coated piston. On the other hand substrate temperature of coated piston is lower than uncoated and decreasing as the hole's radius is increases. The substrate surface temperature for the coated piston, coating with 1.5 mm radius hole, 2 mm radius hole and 2.5 mm radius hole is 287.89 °C, 282.83 °C, 278.82 °C and 273.41 °C respectively. The minimum temperature on substrate surface is observed for coating having hole of 2.5 mm radius which is about 273.41 °C and which is 5.02% lower than coated piston.