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November 4, 2014 at 8:15 am #332
matstral matstral
MemberHi，
I am trying to model the injection system，but i do not understand the Parameter and the units! How to define the start of the injection？ Do someone know that ? Please help ！！！November 4, 2014 at 8:33 am #491sreenathiit12
MemberIn the injection pulse tab you can press the button + in order to add a new injection pulse. The information that you must provide is the start of injection and the percentage of fuel mass injected in the pulse. The mass injected by all pulses must sum 100%.
The coefficients that you show are used to build the shape of the injection rate but I need check the exact meaning of each coefficient because I don’t remember. We usually impose the heat release rate and this capability is not commonly used.
November 4, 2014 at 8:56 am #492Member@farnau wrote:
In the injection pulse tab you can press the button + in order to add a new injection pulse. The information that you must provide is the start of injection and the percentage of fuel mass injected in the pulse. The mass injected by all pulses must sum 100%.
The coefficients that you show are used to build the shape of the injection rate but I need check the exact meaning of each coefficient because I don’t remember. We usually impose the heat release rate and this capability is not commonly used.
ｂｕｔ ｉｆ ｗｅ ｕｓｅ ｔｈｅ ＡＣＴｍｏｄｅｌ，ｃｏｕｌｄ ｉ ａｌｓｏ ｉｍｐｏｓｅｔｈｅ ｈｅａｔ ｒｅｌｅａｓｅ ？ Ｐｌｅａｓｅ ｃｈｅｃｋ ｔｈｅ ｍｅａｎｉｎｇ ｏｆ ｅａｃｈ ｃｏｅｆｆｉｃｉｅｎｔ ．Ｔｈａｎｋ ｙｏｕ ｖｅｒｙ ｍｕｃｈ！
November 4, 2014 at 9:55 am #493MemberACT is an alternative. If you use, you cannot impose heat release law. Regarding your data it has no sense an injection pulse with 0 % of mass. 0.5 + 1 is different to 100%. In openwam, the angle for combustion top dead centre is equal to 0. I will check the meaning of the coefficients later. I don’t have the information available in this moment.
November 4, 2014 at 9:55 am #494MemberACT is an alternative. If you use, you cannot impose heat release law. Regarding your data it has no sense an injection pulse with 0 % of mass. 0.5 + 1 is different to 100%. In openwam, the angle for combustion top dead centre is equal to 0. I will check the meaning of the coefficients later. I don’t have the information available in this moment.
November 4, 2014 at 12:08 pm #495Member@farnau wrote:
ACT is an alternative. If you use, you cannot impose heat release law. Regarding your data it has no sense an injection pulse with 0 % of mass. 0.5 + 1 is different to 100%. In openwam, the angle for combustion top dead centre is equal to 0. I will check the meaning of the coefficients later. I don’t have the information available in this moment.
Thank you very much. please tell me the the meaning of the coefficients later. i will wait for that。
November 4, 2014 at 12:34 pm #496MemberThe coefficients are used to build the injection rate (g/s).
PCR = Rail pressure (bar)
n = engine speed (rpm)
Coefficients A: a (g/s^2) represents the positive slope of the curve at the beginning
a=A1 * PCR + A0
Coefficients B: b (g/s) represents the maximum injection rate.
b=B1 * PCR + B0
Coefficients C: c (g/s^2) represents the negative slope of the curve at the end
c=C1 * PCR + C0
Coefficients D: can be used to shift the pulse and modify the start of injection
SOI = SOP + (D1* PCR + D2) * (6 * n) -
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