Abstract: Model experiments on fluid flow and pattern selection havebeen done by creating flow in liquid region close to the growth fronts indendritic growth of SCN-aceton dilute alloys.The kinetics and morphologyof dendritic growth were measured as a function of thermal gradient,growth velocity and flow velocity.The present paper provides the firststudy of convection effects on constrained dendritic and cellular growthwhich focuses on the tip morphology and develops a boundary layeranalysis.All of the problems addressed have application to the interpreta-tion of the experimental phenomena arising from solodification and fiuiddynamics on earth and space laboratory.