In　this　paper,　three-dimensional　numerical　simulations　with　renormalization-group　(RNG)　k-epsilon　model　are　performed　for　the　air-side　heat　transfer　and　fluid　flow　characteristics　of　wavy　fin-and-tube　heat　exchanger　with　delta　winglet　vortex　generators.　The　Reynolds　number　based　on　the　tube　outside　diameter　varies　from　500　to　5000.　The　effects　of　different　geometrical　parameters　with　varying　attack　angle　of　delta　winglet　(beta=30　deg,　beta=45　deg,　and　beta=60　deg),　tube　row　number　(2-4),　and　wavy　angle　of　the　fin　(theta=0-20　deg)　are　examined.　The　numerical　results　show　that　each　delta　winglet　generates　a　downstream　main　vortex　and　a　corner　vortex.　The　longitudinal　vortices　are　disrupted　by　the　downstream　wavy　trough　and　only　propagate　a　short　distance　along　the　main　flow　direction　but　the　vortices　greatly　enhance　the　heat　transfer　in　the　wake　region　behind　the　tube.　Nusselt　number　and　friction　factor　both　increase　with　the　increase　in　the　attack　angle　beta,　and　the　case　of　beta=30　deg　has　the　maximum　value　of　j/f.　The　effects　of　the　tube　row　number　on　Nusselt　number　and　friction　factor　are　very　small,　and　the　heat　transfer　and　fluid　flow　become　fully　developed　very　quickly.　The　case　of　theta=5　deg　has　the　minimum　value　of　Nusselt　number,　while　friction　factor　always　increases　with　the　increase　in　wavy　angle.　The　application　of　delta　winglet　enhances　the　heat　transfer　performance　of　the　wavy　fin-and-tube　heat　exchanger　with　modest　pressure　drop　penalty.