A perpendicular heating board with staggered circular holes was used to investigate the characteristics of the forced convection heat transfer. The multi-thermocouple was used to measure the temperature distributions in the thermal boundary layer along the wall in order to estimate the local heat transfer coefficient. The validity of the temperature measurement technique was confirmed by comparing under the condition of the natural convection with the theoretical result. The local heat transfer coefficients on the multi-holes board increased, and then heat transfer becomes like as in turbulence flow because the holes caused the turbulence when the fluid passed over the holes.
