This　paper　presents　a　study　on　experiment　and　analysis　of　variable　area-ratio　ejector　used　in　a　multi-evaporator　refrigeration　system　(MERS).　The　experimental　rig　and　method　are　described,　and　the　entrainment　and　pressure　recovery　performances　of　the　variable　ejector　are　measured　at　various　operating　and　geometric　conditions.　The　critical　area　ratio　is　proposed　as　an　indicator　of　pressure　recovery　status;　area　ratios　smaller　than　the　critical　ones　are　required　to　make　sure　that　the　system　operates　at　energy　saving　mode.　The　investigation　results　indicate　that　the　entrainment　ratio,　pressure　recovery　ratio　and　critical　area　ratio　are　strongly　affected　by　the　primary　pressure　and　secondary　pressure.　Greater　entrainment　ratio　can　be　obtained　by　increasing　the　secondary　pressure　or　decreasing　primary　pressure.　The　opposite　trends　are　found　for　pressure　recovery　ratio.　Moreover,　the　critical　area　ratio　varies　greatly　with　the　operation　condition,　and　can　be　predicted　by　a　linear　fitting　function　of　primary　pressure　or　a　power　function　in　terms　of　secondary　pressure.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.