“…An adequate physical explanation for the behavior of the drag force in all range of mixed convection is thus fragmented, especially in the opposed-flow configuration where there are sharp flow transitions because of re-circulation. Only recently experimental studies have been performed on the mixed free-forced-convection phenomenon on small particles that enables the examination of the theoretical studies conducted so far (Bar-Ziv, Zhao, Zhang, & Kantorovich, 1998;Zhao, Kantorovich, Bar-Ziv, & Sarofim, 1998;Katoshevski, Zhao, Ziskind, & Bar-Ziv, 2000;Ziskind, Zhao, Katoshevski, & Bar-Ziv, 2001;Bar-Ziv, Zhao, Mograbi, Katoshevski, & Ziskind, 2002).…”