Negative values in flow rate

[nilza.reis]

Sometimes, in the results of the flow rate, the values are negative. Why?

[nordhb · Accepted solution]

Hi,
basically negative flow rate means a backflow.
The reason for this, is a that cavity is pressurized and when pressure is released at V/P switchover,
the flow follows path of least resistance, and sometimes becomes a backflow through gate, hence negative.
You should be abble to see this on velocity plot, and vectors as darts, how they change direction.
If modeled runner beams, you should be able to see the negative flow rate in beams.

Hope this clarifies.

Regards,
Berndt

[nilza.reis]

thank you!

[JayMuller]

Dear Nilza,

everybody had this before - I wouldn't mind

Moldflow could even flow "filled Volume" backwards:

|   2.996 |  98.360 | 1.146e+02 | 1.09e+02 |    5.076 |   2.94 |   P   |

|   3.004 |  98.369 | 1.146e+02 | 1.10e+02 |    4.815 |   2.97 |   P   |

|   3.014 |  98.380 | 1.146e+02 | 1.12e+02 |    4.033 |   3.00 |   P   |

|   3.030 |  98.397 | 1.146e+02 | 1.14e+02 |    3.194 |   3.07 |   P   |

|   3.073 |  98.445 | 1.146e+02 | 1.15e+02 |    2.203 |   3.23 |   P   |

|   3.222 |  98.577 | 1.146e+02 | 1.12e+02 |    1.124 |   3.84 |   P   |

|   3.821 |  98.579 | 1.146e+02 | 9.00e+01 |    0.495 |   6.99 |   P   |

|   4.821 |  98.567 | 1.146e+02 | 5.44e+01 |    0.168 |  13.63 |   P   |

|   5.821 |  98.556 | 1.146e+02 | 2.90e+01 |    0.069 |  23.45 |   P   |

|   6.821 |  98.549 | 1.146e+02 | 1.63e+01 |    0.053 |  38.08 |   P   |

|   7.821 |  98.542 | 1.146e+02 | 1.12e+01 |    0.048 |  59.25 |   P   |

Funny isn't it.