The Effect of Viscosity Ratio and Peclet Number on Miscible Viscous Fingering in a Hele-Shaw Cell: A Combined Numerical and Experimental Study

The results from a series of well characterised, unstable, miscible displacement experiments in Hele-Shaw cell with quarter five-spot source-sink geometry are presented, comparisons to detailed numerical simulation. We perform repeated at adverse viscosity ratios 1 20 and Peclet numbers 10 $$^4$$ $$^6$$ capturing the transition 2D 3D radial fingering experimental uncertainty. open-access dataset provides time-lapse images patterns, transient effluent profiles, meta-information for use model validation. find complexity pattern increases ratio number, onset is delayed compared linear displacements, likely due Taylor dispersion stabilisation. occurs critical number that consistent recent literature. simulations hydrodynamic different mesh orientations provide good predictions breakthrough times sweep efficiency obtained intermediate across range tested, generally within Specific finger wavelengths, tip shapes, growth hard replicate; using velocity-dependent longitudinal or simple molecular diffusion bound evolution seen experiments, but neither fully capture both fine-scale macroscopic measures. In cases, predict sharper fingers than experiment. A weaker stabilisation seems necessary high ratio, which may also require anisotropic components. models varying formulations should be explored future developments full effects number.