# Topic: Re: Is there a formula to calculate axial thrust?

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The axial thrust on a tank of any geometry is in response (and directly opposite) to the axial thrust generated by the impeller on the submersible mixer.&nbsp; In general, the local thrust on the walls of the tank will be small.&nbsp; The primary effect of the axial thrust from the mixer will be on the mixer support.&nbsp;Axial thrust is a characteristic of the impeller design and a function of the impeller geometry and operating conditions.&nbsp; All geometrically similar impellers will have a characteristic thrust number (similar to a power number), which will be a constant for turbulent conditions.&nbsp; Turbulent conditions are typically represented by an impeller Reynolds number greater than 20,000.&nbsp; Although the thrust number will be nearly constant (less that 2% deviation) down to perhaps a Reynolds number of 2,000.&nbsp; Your solids concentration will only enter the thrust number, with respect density and viscosity in the Reynolds number.&nbsp;The thrust number is the axial thrust force generated by the impeller divided by fluid density, rotational speed squared and impeller diameter to the fourth power.&nbsp; In consistent units, the thrust number is dimensionless and the value is independent of the units used to calculate it.&nbsp; The value of the thrust number must be developed experimentally or from the impeller geometry, consistent with the type of impeller used on the mixer.&nbsp; That thrust number can be used to calculate an axial thrust, by evaluation with specific conditions for fluid density, impeller rotational speed and impeller diameter.&nbsp; The Reynolds number represented by impeller diameter squared, times rotational speed, times fluid density, divided by viscosity.&nbsp; Also a dimensionless group.&nbsp;
Here are the general equations for the Thrust Number and Reynolds Number (click on links).
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