## General

#### How to setup the mass flow rate of DPM point injection in 2D and in 2D Axisymmetric in ANSYS FLUENT?

• FAQ
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The manual explains the difference between 2D axisymmetric and 2D non-axisymmetric. 2D non-axi-symmetric: the model will consider that your injection (which will have the form of a slot â€“ collection of injections points on a line of a meter long) is 1 meter long in the 3rd dimension. This implies that if your device is 0.,25 m in the non-simulated dimension, you will have to use a mass flow rate 4 times higher (x kg/s per 0.25 m = 4x kg/s per meter). 2D axi-symmetric: per 2pi radiant also means per 360 degree or for the entire circle. In this case, FLUENT will assume that your injection is a circle of 360 degrees, i.e. a collection of injection points along a circle. For example, if you define an injection point at x = 0, y = 0.5 m (z is the axis of revolution) with a mass flow rate of 1 kg/s, you will actually be modeling an injection which is a circle of radius 0.5 and center x = z = y = 0.0 and a mass flow rate of 1 kg/s. In conclusion, if you are modeling this type of injection (a circle), then you do not have to divide your mass flow rate. If your problem (in 3D) only has 1 injection point, then there is no problem because this is not an axisymmetric problem and need to be modelled in 3D.