Over the last years, there has been a high interest in carbon nanotubes' (CNTs) applications due to their unique properties, mainly at mechanical and electrical levels. However, current synthesis processes, such as chemical vapor deposition (CVD), are highly unpredictable and inconsistent, which leads to an exhaustive trial-and-error methodology when extrapolating results. A sensitivity analysis based on computational fluid dynamics (CFD) is performed here to two distinct setups of the CVD process as a way to understand the synthesis process. Setups were computationally designed and simulated for various synthesis scenarios, where only the hydrocarbon flow and the process temperature were changed. Measuring synthesis conditions, such as concentrations and velocity, inside the tube furnace, for these scenarios allows the identification of which compound affects most each condition. Results showed that, when envisioning the process extrapolation, the synthesis conditions can be tuned via the accessed parameters.