By　using　the　commercial　software　ANSYS　CFS,　numerically　calculated　were　the　heat　exchange　characteristics　of　the　cooling　air　inside　a　straight　ribbed　rectangular　channel　and　compared　were　the　calculation　results　with　the　test　data　obtained　by　Han.　Furthermore,　the　influence　of　Reynolds　and　the　angle　of　ribs　on　Nusselt　number　was　also　analyzed.　It　has　been　found　that　the　average　Nusselt　number　obtained　from　the　numerical　calculation　assumes　an　identical　variation　tendency　to　the　test　values.　The　calculation　results,　however,　were　bigger　than　the　test　values.　Due　to　the　flow　disturbance　role　played　by　the　ribs,　two　vortexes　will　be　produced　in　the　zone　between　any　two　ribs,　enhancing　the　heat　exchange　between　the　cooling　air　and　the　solid　wall　surfaces.　With　an　increase　of　Reynolds　and　Nusselt　number,　the　average　friction　resistance　coefficient　will　also　increase.　When　the　angle　of　ribs　falls　in　a　range　from　45　to　60　degrees,　the　intensified　convection　heat　exchange　effectiveness　in　the　cooling　channel　is　assessed　as　the　best.