Flow and mixing characteristics of a forward-inclined stack-issued jet in crossflow

•Increasing forward inclination angle of jet tube in crossflow dominated regimes eliminated the upwind-side shear-layer vortices.•increasing forward inclination angle of jet tube in jet flow dominated regimes emphasized the upwind-side shear-layer vortices.•Increasing the forward inclination angle of jet tube at fixed jet-to-crossflow momentum flux ratio increased the jet spread width in the far field.•In the jet flow dominated regimes, higher forward inclination angles associated with low maximum jet fluid concentrations. The flow and mixing characteristics of a forward-inclined stack-issued jet at various inclination angles (θ) and jet-to-crossflow momentum flux ratios (R) were experimentally studied in an open-loop wind tunnel. Flow behaviors were examined using the laser-assisted smoke flow visualization technique. The instantaneous velocities of the upwind-side shear-layer were digitized by a hot-wire anemometer using a high-speed data acquisition system. The instability frequencies in the upwind-side shear-layer vortices were obtained by the fast Fourier transform method. Long-exposure flow images were processed using the binary edge-detection technique to obtain the jet spread width. Transverse dispersion of jet fluids was determined using tracer gas concentration detection. The upwind-side shear-layer vortices revealed four characteristic flow modes: the High impingement-crossflow dominated mode (about θ 25° and high R). Increasing θ in the crossflow dominated regimes eliminated the upwind-side shear-layer vortices, while increasing θ in the jet flow dominated regimes emphasized the upwind-side shear-layer vortices. Increasing θ at a fixed value of R increased jet spread width in the far field in all modes. In the near field, at x/d