In his seminal paper on the solution of infiltration equation, Philip (1969), https://doi.org/10.1016/b978-1-4831-9936-8.50010-6 proposed a gravity time, tgrav, to estimate practical convergence time and domain validity infinite series expansion, TSE, for describing transient state. The parameter tgrav refers point in where is dominated equally by capillarity as derived from first two (dominant...