A　prototype　clutch　having　horizontal　rotational　axis　and　a　narrow　gap　between　its　two　parallel　radial　disks　is　examined　using　computational　fluid　dynamics　(CFD).　The　narrow　gap　between　the　discs　is　filled　with　an　unexcited　electrostructured　fluid　(ESF);　the　throughflow　of　electrorheological　(ERF)　or　magnetorheological　(MRF)　fluid　that　would　arise　is　contemplated　as　a　means　of　contributing　towards　the　cooling　of　the　clutch.　The　throughflow,　caused　by　body/centrifugal　force　action,　is　examined　first　when　both　plates　rotate　together　at　a　speed,　Omega.　The　aim　is　to　estimate　the　flow　rates　arising　under　conditions　of　different　rotational　velocities,　clutch　geometries,　and　fluid　properties.　Following　this,　the　cooling　of　the　clutch　is　examined　for　the　case　of　one　plate　fixed　and　the　other　rotating　at　a　constant　speed　throughout.　The　inlet　and　outlet　port　pressures　are　made　the　same　and　the　fluid　is　taken　to　be　unexcited/Newtonian　with　viscosity　mu.