Experimental Investigation of Heat Transfer to a Dual Jet Flow with Varying Velocity Ratio

Dual jet flow is a topical area of research due to their wide range of current and potential uses in industry. Despite this, there is still a lack of published studies which focus on the characterization of dual jet flow, particularly regarding their heat transfer capabilities. The objective of this investigation is to therefore build upon the available dual jet data and conduct an experimental study which focusses on the effect of the jet velocity ratio on heat transfer to a dual jet flow for a constant offset ratio of 3, where air is used as the working fluid. The wall and offset jet velocities are each varied between
$\mathbf{5500} \leq \boldsymbol{Re}\leq \mathbf{12000}$
to create a range of velocity ratios from
$\mathbf{0}.\mathbf{5}\leq \boldsymbol{V}_{\boldsymbol{r}}\leq \mathbf{2}$
. A uniform heat flux of 2500 W/m
²
is maintained in the bounding wall and the local Nusselt number data is derived from temperature measurements acquired through infra-red thermography. The results show a strong dependence on the velocity ratio, where, for a constant total mass flow rate, increasing the velocity ratio increased the value of a localized minimum Nusselt number and moved its location closer to the jet exit. In addition, increasing the total mass flow rate elevated
$\boldsymbol{Nu}_{\boldsymbol{x}}$
across all downstream locations for each
$\boldsymbol{V}_{\boldsymbol{r}}$
examined.