Hot-wire and PIV characterisation of a novel small-scale turbulent channel flow facility developed to study premixed expanding flames

We demonstrate a small-scale channel flow facility with passive and active turbulence generators for the study of spherically expanding turbulent flames. Traditionally, this canonical flame type is investigated in stagnant cylindrical combustion chambers with imposed turbulence. Incorporating a convective flow allows for a wider variety of flowfields and turbulence conditions to be studied. We compare the turbulence properties of our novel facility with cylindrical chambers and large-scale wind tunnels, discussing the design and validation strategy along with quantifiable turbulence properties. Measurements are made utilising hot-wire anemometry (HWA) and particle image velocimetry (PIV). The turbulent properties are analysed for a range of Reynolds numbers (Re_λg 130–480, computed from streamwise RMS velocities and transverse Taylor microscales). Comparing PIV results with HWA, emphasise is put on the achievement of sensible estimates for small-scale quantities relevant to mixing. The facility is demonstrated to have the requisite capability to study expanding premixed flame kernels under the influence of intense turbulence in a windtunnel-like configuration with no precedence in the literature. Based on several criteria, it is shown that homogeneous isotropic turbulence can be achieved in much smaller dimensions than expected from classic windtunnel studies.