Heat transfer enhancement by V-shaped protrusions on jet plate under different crossflow conditions

This paper studies the effect of jet plate V-shaped protrusions (VP) on impingement cooling at the crossflow-to-jet mass flow ratio (CMFR) ranging from 0 to 0.5. The effects of location (L), height (H), open angle (θ) of VP and crossflow-to-jet temperature ratio (TR) are discussed. From results, compared with Baseline case (impingement cooling without VP), all VP cases can enhance heat transfer (Nu_ave), although friction loss coefficient (f) also increase, thermal performance factor (TPF) are improved. When L varies from 1.5D to 3.0D, VP case with L of 1.5D has the highest Nu_ave and f, and at CMFR of 0.5, it owns the highest TPF of 1.081. When H increases from 0.1D to 0.4D, Nu_ave, f and TPF gradually increase. However, when H varies from 0.4D to 0.5D, only Nu_ave and f also increase, TPF increases only at CMFR ranging from 0.4 to 0.5. Besides, with the increase of θ, Nu_ave, f and TPF increase, and VP case with the θ of 110° always obtains the highest TPF. At CMFR of 0.5, TPF is up to 1.098. Finally, for impingement cooling with/without VP, as TR increases, the heat transfer always decreases.