[{"key":"dc.contributor.author","value":"Birger, Nicholas Joseph","language":null},{"key":"dc.date.accessioned","value":"2010-06-14T16:28:28Z","language":null},{"key":"dc.date.available","value":"2010-06-14T16:28:28Z","language":null},{"key":"dc.date.issued","value":"2010","language":null},{"key":"dc.identifier.uri","value":"http:\/\/hdl.handle.net\/2429\/25752","language":null},{"key":"dc.description.abstract","value":"Natural gas has a high auto-ignition temperature, therefore natural gas engines use an\nignition source to promote combustion. The high-pressure direction-injection (HPDI)\nsystems available use small diesel injections prior to the main gas injection. A new series\nof HPDI injectors have been developed that inject diesel and gas simultaneously through\nthe same holes. In order to understand and control injection and combustion behavior in\nan engine, it is essential to understand how injection mass is related to the diesel\/gas ratio\nand injection command parameters.\nThree prototype injectors are examined. \u201cPrototype B\u201d most closely resembles a standard\nJ36 HPDI injector, but has a modified diesel needle that injects diesel internally into a\ncommon diesel\/gas reservoir. Prototypes \u201cCS & CSX\u201d have the diesel needle eliminated\nand replaced with a flow restrictor. The pressure difference between the diesel and the\ngas controls the quantity of diesel injected. A single pulse width (GPW) for the gas\nneedle controls the fuel quantities.\nAn injection visualization chamber (IVC) was developed for flow measurements and\noptical characterization of injections into a chamber at pressures up to 80 bar. Diesel and\nnatural gas are replaced by VISCOR\u00ae and nitrogen to study non-reacting flows. A novel\nfeature of the IVC is a retracting shroud that allows the injector to reach steady-state prior\nto imaging.\nFor low commanded injection duration (GPW less than 0.60 ms), the relation between\nGPW and injected mass is non-linear, for all injectors tested. For gas pulse widths greater\nthan 0.65 ms the Co-injectors exhibit approximately linear behavior with higher diesel\nfuelling quantities lowering gas flow quantities. All Co-injectors are compared to\nbaseline gas flow quantities of a standard J36 to show design difference effects on flow\nquantities. The sensitivity of gas flow to diesel in injection quantities, as well as the\ndischarge coefficient are computed and theoretically modeled for each prototype. Results\nsuggest differing diesel\/gas distributions, dependent on method of diesel introduction and\nactuator response.\nImaging indicates the mechanical delay of the injectors is independent of chamber\nbackpressure but dependent on fuel supply pressure. However, gas injection quantities\nare increased by higher chamber backpressure. Changes in the gas\/liquid ratio are\nreflected in different jet image characteristics. These results are compared to theory using\nan AMESim model developed for an existing production injector.","language":"en"},{"key":"dc.language.iso","value":"eng","language":"en"},{"key":"dc.publisher","value":"University of British Columbia","language":null},{"key":"dc.rights","value":"Attribution-NonCommercial-NoDerivatives 4.0 International","language":null},{"key":"dc.rights.uri","value":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/","language":null},{"key":"dc.title","value":"Flow characteristics of gas-blast fuel injectors for direct-injection compression-ignition engines","language":"en"},{"key":"dc.type","value":"Text","language":null},{"key":"dc.degree.name","value":"Master of Applied Science - MASc","language":"en"},{"key":"dc.degree.discipline","value":"Mechanical Engineering","language":"en"},{"key":"dc.degree.grantor","value":"University of British Columbia","language":"en"},{"key":"dc.date.graduation","value":"2010-05","language":"en"},{"key":"dc.type.text","value":"Thesis\/Dissertation","language":"en"},{"key":"dc.description.affiliation","value":"Applied Science, Faculty of","language":null},{"key":"dc.description.affiliation","value":"Mechanical Engineering, Department of","language":null},{"key":"dc.degree.campus","value":"UBCV","language":"en"},{"key":"dc.description.scholarlevel","value":"Graduate","language":"en"}]