This paper presents a study on the thermal conductivity of carbon nanotubes (CNTs) using molecular dynamics (MD) simulations. The research focuses on understanding how the thermal conductivity of CNTs depends on their structure, defects, and vacancies. The study uses an empirical bond order dependent force field to model the thermal transport properties of CNTs. The results show that CNTs have very high thermal conductivity, comparable to diamond and in-plane graphite sheets. The anisotropic nature of thermal conductivity in graphite is reflected in CNTs, with significant differences in thermal conductivity along different crystal axes. The study also investigates the effect of defects and vacancies on the thermal conductivity of CNTs. It is found that the thermal conductivity decreases with increasing vacancy concentration, but the rate of decrease is not as severe as expected. Similarly, conformational defects, such as the (5,7,7,5) defect, also reduce thermal conductivity, but the effect is less pronounced than in three-dimensional materials. The study also examines the thermal conductivity of nanotube bundles, which show high thermal conductivity along the tube axis, comparable to that of graphite. The thermal conductivity in the direction perpendicular to the tube is much lower, similar to that of graphite. The results indicate that CNTs have high thermal conductivity, which is important for thermal management in nanoscale devices. The study highlights the importance of understanding the thermal transport properties of CNTs for their application in MEMS and NEMS. The findings suggest that CNTs could be a promising material for thermal management in nanoscale devices due to their high thermal conductivity. The study also emphasizes the need for further research to understand the underlying mechanisms of thermal conductivity in CNTs.This paper presents a study on the thermal conductivity of carbon nanotubes (CNTs) using molecular dynamics (MD) simulations. The research focuses on understanding how the thermal conductivity of CNTs depends on their structure, defects, and vacancies. The study uses an empirical bond order dependent force field to model the thermal transport properties of CNTs. The results show that CNTs have very high thermal conductivity, comparable to diamond and in-plane graphite sheets. The anisotropic nature of thermal conductivity in graphite is reflected in CNTs, with significant differences in thermal conductivity along different crystal axes. The study also investigates the effect of defects and vacancies on the thermal conductivity of CNTs. It is found that the thermal conductivity decreases with increasing vacancy concentration, but the rate of decrease is not as severe as expected. Similarly, conformational defects, such as the (5,7,7,5) defect, also reduce thermal conductivity, but the effect is less pronounced than in three-dimensional materials. The study also examines the thermal conductivity of nanotube bundles, which show high thermal conductivity along the tube axis, comparable to that of graphite. The thermal conductivity in the direction perpendicular to the tube is much lower, similar to that of graphite. The results indicate that CNTs have high thermal conductivity, which is important for thermal management in nanoscale devices. The study highlights the importance of understanding the thermal transport properties of CNTs for their application in MEMS and NEMS. The findings suggest that CNTs could be a promising material for thermal management in nanoscale devices due to their high thermal conductivity. The study also emphasizes the need for further research to understand the underlying mechanisms of thermal conductivity in CNTs.