Abstract: The deposition of particulate matter in heat exchanger channels can greatly reduce their heattransfer efficiency, and a better understanding of the deposition characteristics of particulate matter inheat exchanger channels is essential for improving heat exchanger performance. The deposition charac⁃teristics of particles in a three-dimensional dimpled dimple channel were simulated using the ReynoldsStress Model (RSM) and Discrete Particle Model (DPM). The flow structure, secondary flow, temper⁃ature distribution and particle deposition distribution in the dimpled dimple channel were analyzed andinvestigated after mesh -independence testing and numerical validation. The results showed that themain mechanisms affecting the particle deposition characteristics in dimpled dimple channels were grav⁃ity, thermophoretic forces, turbulent flow structure, secondary flow and particle inertia, and the effectsof these mechanisms change significantly with particle size. For small particles ( dp ≤ 10 μm), thepresence of the dimpled dimple structure promoted deposition; however, for large particles ( dp > 10μm), its presence had only a small effect on the distribution of particle deposition locations.