In t he present stud y, the infl uenc e of incl ined horseshoe s baffl es pla ced repeatedly in a tubul ar heat
exchan ger on heat transfer rate, friction factor an d thermal enh ancemen t factor are exper imental ly
determined. The hor seshoe baffl e eleme nts wit h an inclina tion ang le of 20 were inserted periodic ally
into the test tube at three dif ferent baffl e-pitch ratios (PR ¼ 0.5, 1.0 and 2) and -width or blockage ratios
(BR ¼ 0.1, 0.15 and 0.2). The experiment was conducted in the test tube having a uniform heat-fluxed wall
by varying turbulent airflow to obtain Reynolds number in a range of 5300e24,000. The experimental
results revealed that the tube fitted with inclined horseshoes baffles provides considerable improvement
of the heat transfer rate over the plain tube around 92e208% while the friction factor is increased at
about 1.76e6.37 times. To access the real benefits for the inclined horseshoes baffles inserted in plain
tube, thermal performance factor is examined and found to be in the range of 1.34e1.92 at which the
maximum obtained at PR ¼ 0.5 and BR ¼ 0.1 is considerably higher than that for published inserted
devices. Correlations for Nusselt number and friction factor for the oblique horseshoe-baffled tube are
also proposed.