Heat flux is a key concept in thermodynamics and heat transfer. It refers to the amount of heat energy flowing through a unit area per unit time, and its SI unit is watts per square meter (W/m²). Its physical meaning is to quantify the intensity of heat transfer, reflecting the efficiency and direction of heat flow in a system. It is a core indicator for analyzing heat transfer processes1. Heat flux is directional and follows the basic law of "heat transfer from high temperature areas to low temperature areas." For example, when a high-temperature object dissipates heat to the surrounding environment, the heat flux is directed toward the surrounding environment. https://www.renkeer.com/what-is-heat-flux/