Frictional resistance coefficient during air transport by continuous flow

Conclusions

• 1. The following dependence of the resistance coefficient on the Froude parameter was obtained for all the materials experimented with:

  $$\lambda = 4.25\left( {\frac{D}{d}} \right)^{0.5} Fr^{ - 0.75} .$$

• 2. In determining the resistance coefficient, it is recommended that the total loss in head in air-transport by continuous flow should be calculated by the following expression:

  $$\Delta P = \Delta P_{fr} + \Delta P_{st} = \left[ {2,125\left( {\frac{{V_r }}{D}\sqrt {\frac{d}{g}} } \right)^{0,5} + 1} \right]j_C (1 - \varepsilon )Lkg/m^2 $$