In the present study a methodology has been proposed to evaluate, the performance of the V down perforated baffle roughened rectangular channel using hybrid FAHP-FOPSIS approach. The hybrid FAHP (fuzzy analytical hierarchy process) and FTOPSIS (fuzzy technique for order preference by similarity of an ideal solution) approach, taking into account PDAs (performance defining attributes), such as Nusselt number ratio, friction factor ratio, thermohydraulic performance parameter and effective efficiency, was used for the performance prediction of the V down perforated baffle roughened rectangular channel. The weight of different PDAs was evaluated by FAHP; Nu(rat) (0.060, 0.093, 0.138), f(rat) (0.045, 0.066, 0.105), epsilon (0.170, 0.244, 0.352) and eta(eff) (0.431, 0.597, 0.821), respectively. FTOPSIS was employed to determine the optimum ranking of the V down perforated baffle roughened rectangular channel and the values obtained as; C6 > C5 > C8 > C7 > C9 > C10 > C2>C11 > C12 > C1 > C3 > C13 > C14 > C4 > C15 > C16. The test plate (alternative) with an open area ratio (beta) of 24%, relative roughness pitch (P/e) of 2 and relative roughness height (e/H) of 0.4, exhibits the optimal formulation. (C) 2015 Elsevier Ltd. All rights reserved.