TY - JOUR
TI - Numerical study on heat transfer deterioration of n-decane during pyrolysis under supercritical pressure in a vertical tube
AU - Lei Zhiliang
AU - Bao Zewei
JN - Thermal Science
PY - 2024
VL - 28
IS - 6
SP - 4723
EP - 4735
PT - Article
AB - For accelerating hypersonic vehicles, it is important to understand the  effects of various factors on heat transfer deterioration. The heat transfer  characteristics of supercritical n-decane with pyrolysis were numerically  simulated inside a vertical tube. The effects of flow direction, mass flow  rate, heat flux, inlet temperature, and flight acceleration on the heat  transfer characteristics were investigated. When the inlet temperature was  relatively low or the fluid was decelerated vertically upward, a typical  M-shaped velocity distribution was formed, indicating the heat transfer  deterioration (HTD). Furthermore, the decrease in wall heat flux, as well as  the increase in mass flow rate, inlet temperature and flight acceleration in  the same direction as the flow makes the HTD gradually disappear. Finally, a  new relationship was established between the heat flux and the flight  acceleration and inlet temperature to determine critical heat flux under  which HTD developed in the upward flow.