Technology​ ​award​ ​for​ ​wave​ ​piston​ ​design​ ​that​ ​lowers​ ​fuel​ ​consumption

Thursday, June 22, 2017



Engineers​ ​behind​ ​Volvo​ ​Group’s​ ​new​ ​more​ ​fuel-efficient​ ​truck​ ​engines​ ​have received​ ​the​ ​Volvo​ ​Technology​ ​Award​ ​2017.

Jan​ ​Eismark​ ​and​ ​colleague​ ​Michael​ ​Balthasar​ ​came​ ​up​ ​with​ ​an​ ​intelligent piston​ ​design​ ​by​ ​adding​ ​waves​ ​to​ ​the​ ​piston​ ​crown​ ​to​ ​improve​ ​the​ ​use​ ​of oxygen.

In​ ​the​ ​case​ ​of​ ​a​ ​standard​ ​piston,​ ​the​ ​injector​ ​is​ ​located​ ​at​ ​the​ ​top​ ​of​ ​the cylinder​ ​and​ ​the​ ​fuel​ ​is​ ​sprayed​ ​toward​ ​the​ ​sides​ ​of​ ​the​ ​cylinder​ ​through​ ​a number​ ​of​ ​openings​ ​in​ ​the​ ​injector.​ ​The​ ​combination​ ​of​ ​heat​ ​and​ ​pressure causes​ ​the​ ​fuel​ ​to​ ​ignite​ ​before​ ​it​ ​reaches​ ​the​ ​cylinder​ ​wall.

The​ ​flame​ ​hits​ ​the​ ​wall​ ​of​ ​the​ ​combustion​ ​chamber​ ​at​ ​a​ ​speed​ ​of​ ​up​ ​to​ ​50 metres​ ​per​ ​second,​ ​spreads​ ​along​ ​the​ ​piston​ ​bowl​ ​wall​ ​and​ ​then​ ​collides​ ​with adjacent​ ​flames​ ​at​ ​an​ ​angle​ ​of​ ​180​ ​degrees,​ ​while​ ​still​ ​traveling​ ​at​ ​a​ ​high speed.

When​ ​the​ ​flames​ ​collide,​ ​they​ ​compete​ ​for​ ​the​ ​available​ ​oxygen,​ ​but​ ​the oxygen​ ​in​ ​the​ ​centre​ ​of​ ​the​ ​combustion​ ​chamber​ ​is​ ​never​ ​fully​ ​used.

“For​ ​this​ ​reason,​ ​we​ ​wanted​ ​to​ ​identify​ ​a​ ​method​ ​of​ ​leading​ ​the​ ​flames​ ​into​ ​the centre​ ​of​ ​the​ ​combustion​ ​chamber​ ​to​ ​make​ ​better​ ​use​ ​of​ ​the​ ​oxygen​ ​there,” explains​ ​Eismark.

The​ ​result​ ​of​ ​their​ ​work​ ​was​ ​the​ ​inclusion​ ​of​ ​ridges​ ​or​ ​waves​ ​in​ ​the​ ​piston crown.​ ​The​ ​piston​ ​has​ ​six​ ​ridges​ ​and​ ​the​ ​injector,​ ​which​ ​is​ ​located​ ​in​ ​the centre​ ​of​ ​the​ ​cylinder​ ​at​ ​the​ ​top​ ​of​ ​the​ ​piston,​ ​has​ ​six​ ​openings​ ​to​ ​ensure​ ​the fuel​ ​is​ ​sprayed​ ​between​ ​the​ ​ridges​ ​that​ ​lead​ ​the​ ​flames​ ​into​ ​the​ ​centre.

Extensive​ ​work​ ​has​ ​gone​ ​into​ ​ensuring​ ​the​ ​design​ ​is​ ​cost-effective,​ ​followed by​ ​thousands​ ​of​ ​hours​ ​of​ ​testing​ ​to​ ​refine​ ​the​ ​design​ ​and​ ​verify​ ​the​ ​durability​ ​of the​ ​new​ ​concept.

This​ ​innovative,​ ​intelligent​ ​solution​ ​is​ ​now​ ​in​ ​use​ ​in​ ​the​ ​latest​ ​engines​ ​from​ ​the Volvo​ ​Group​ ​and​ ​brings​ ​advantages​ ​for​ ​both​ ​customers​ ​and​ ​the​ ​environment. The​ ​more​ ​efficient​ ​combustion​ ​process​ ​it​ ​delivers​ ​has​ ​halved​ ​the​ ​quantity​ ​of soot​ ​particles​ ​emitted​ ​by​ ​the​ ​engine​ ​and​ ​has​ ​also​ ​reduced​ ​fuel​ ​consumption by​ ​an​ ​average​ ​of​ ​two​ ​percent.

”For​ ​heavy​ ​vehicles,​ ​diesel​ ​engine​ ​technology​ ​will​ ​be​ ​important​ ​for​ ​many​ ​more years​ ​to​ ​come,”​ ​says​ ​Lars​ ​Stenqvist,​ ​Volvo​ ​Group​ ​chief​ ​technology​ ​officer.​ ​“I am​ ​proud​ ​of​ ​our​ ​engineers​ ​who​ ​have​ ​once​ ​again​ ​shown​ ​that​ ​innovative solutions​ ​can​ ​still​ ​make​ ​engines​ ​more​ ​efficient​ ​for​ ​the​ ​benefit​ ​of​ ​our​ ​customers and​ ​of​ ​society​ ​as​ ​a​ ​whole.”