{
  "$type": "site.standard.document",
  "description": "A method of monitoring exhaust gas flow through an exhaust system of an internal combustion engine comprises the steps of generating a flow efficiency value (KE), comparing the flow efficiency value to a reference efficiency value, and if the reference efficiency value is exceed by a predetermined…",
  "path": "/patents/1111701",
  "publishedAt": "2001-07-11T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N11/00",
    "FORD GLOBAL TECH INC [US]"
  ],
  "textContent": "A method of monitoring exhaust gas flow through an exhaust system of an internal combustion engine comprises the steps of generating a flow efficiency value (KE), comparing the flow efficiency value to a reference efficiency value, and if the reference efficiency value is exceed by a predetermined amount, then setting a flow fault indicator flag. In one aspect of the invention, the flow efficiency value is generated as a ratio of the magnitude of the exhaust gas flow restriction, and the mass flux through the engine. The magnitude of the exhaust gas flow restriction is represented by the pressure drop across the exhaust system, and the mass flux through the engine is determined as a function of the mass airflow rate and exhaust gas density. The resulting flow efficiency value (KE) is a non-dimensional parameter that characterises the level of restriction in the exhaust system independent of the engine operating conditions.",
  "title": "Exhaust system monitoring"
}