As　major　equipment　for　implementing　technological　process,　Shell-and-Tube　Heat　Exchangers　are　widely　used　in　modern　industries.　Because　the　noise　propagation　in　pipelines　in　shell-and-tube　heat　exchangers　can＇t　be　ignored,　it　is　a　key　point　to　investigate　the　transfer　mechanism　of　sound　energy　in　pipelines　and　develop　high　efficiency　mufflers　with　low　penalty　of　pressure　drop.　Different　with　the　traditional　method,　this　study　is　focused　on　the　flow　and　sound　fields　synergy　principle　to　investigate　the　flow　noise　propagation　mechanism　in　pipelines.　In　this　study,　theoretical　analysis　and　numerical　simulation　methods　are　coupled　to　investigate　the　pipeline　noise　propagation　process.　Based　on　the　momentum　and　the　energy　equations　in　the　sound　field,　the　synergetic　relationship　between　the　flow　field　and　the　pressure　gradient　field　is　deduced,　and　the　field　synergy　theory　is　established.　The　flow　noise　propagation　process　of　noise　in　the　pipeline　is　studied　by　numerical　simulation.　The　synergy　is　verified　by　analyzing　the　calculating　results　of　flow　and　sound　fields.　The　results　show　that　with　the　increase　of　synergy　between　flow　and　sound　fields,　the　work　done　by　the　fluid　on　the　wall　increases,　which　means　the　exchange　of　sound　energy　between　the　wall　and　the　fluid　increases.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.