6), such that the difference between the entrance loss predicted by a finite element simulation and the corresponding experimental data for a range of flow rates in capillary or slit rheometer is minimized.
Therefore, an analysis based upon a purely elongational flow, such as the sink flow analysis of Metzner and Metzner , is expected to have a large error in the estimated entrance loss and elongational viscosity.
The planar and axisymmetric elongational viscosities of two LDPEs and polystyrenes were estimated by minimizing the difference between the entrance loss predicted by a finite element simulation and the corresponding data from slit and capillary rheometers, respectively.
10, 11, 14, and 15, the entrance loss predicted by the PELDOM software including the elongational viscosity effects is in good agreement with the experimental data at higher flow rates.
9, 14 and 19 that the entrance flow simulation always converged if the entrance loss in terms of the equivalent length of the downstream channel, [L.
Figures 18 and 19, respectively, show the pressure along the axis of symmetry and the corresponding entrance loss at various flow rates.
Extra pressure loss and vortex length predicted by a finite element simulation of entrance loss are compared with the corresponding predictions from Binding's approximate analysis.
By separately calculating the pressure drop due to shear and elongational flow near an abrupt contraction, Cogswell  developed analytical expressions for an approximate calculation of entrance loss in a fluid with different power-law indices for shear and elongational viscosities.
The design coefficients derived in this study were the entrance loss coefficients, which are the numbers multiplied by the velocity head to estimate the entrance energy loss for a culvert operating in outlet control where the headwater depth is influenced by tail water and friction in the culvert as well as the entrance loss.
The values for the entrance loss coefficient for the field-cast models with straight wingwalls were almost identical for the single-, double-, triple-, and quad-barrel models and averaged 0.
The average entrance loss coefficient increased from 0.
3, combined with this entrance loss
, is an accurate predictor of the behavior of the guide.