# Numerical Study of the Filtration Performance for Electrospun Nanofiber Membranes
## 3 Results and Discussion
### Numerical Simulation Study on the Filtration Efficiency of Electrospun Nanofiber Membranes  
Filtration efficiency is one of the key indicators for measuring filtration performance. There is a close relationship between the two. Usually, higher filtration efficiency means better filtration performance. The FilterDict module is used to simulate the filtration process. The experimental measurement and simulation results of the filtration efficiency of the fiber filter medium are shown in Figures 8 and 9. Filtration efficiency (E) was calculated using the formula: E = (1 - C\({}_{2}\)/C\({}_{1}\)) \(\times\) 100%, where C\({}_{1}\) and C\({}_{2}\) are the upstream and downstream particle concentrations, respectively. Pressure drop (\(\Delta\)P) across the membrane was measured as the difference between upstream (p\({}_{1}\)) and downstream (p\({}_{2}\)) static pressures. The quality factor (QF), which evaluates the comprehensive filtration performance, was defined as QF = \(-\)ln(1 - E/100)/\(\Delta\)P.  
From Figures 8 and 9, it can be seen that the numerical simulation results of the filtration efficiency of electrospun nanofibers are higher than the experimental measurement results of real fiber filter materials, but the deviation is within 7%. The difference between the numerical simulation results of the filtration efficiency of the electrospun nanofiber filter model and the experimental test results of the real material can be attributed to the difference between the model hypothesis and the actual situation. For example, the distribution of fibers is more uniform, and the fiber morphology is more simplified. These assumptions made by the fiber filter medium model may be different from the real nanofiber structure, resulting in a difference between the numerical simulation results and the experimental measurement results. The numerical simulation results are higher than the experimental measurement results of real materials due to the selection of the particle collision model. In the simulation process of particle filtration, the elastic collision effect  
Figure 8: Experimental measurement and numerical simulation results of filtration efficiency of filter media with different spinning solution concentrations.  
Figure 9: Experimental measurement and numerical simulation results of filter media filtration efficiency at different spinning times.  
Based on this, combined with the FilterDict module in GeoDict software, the electrospinning nanofiber filter material model generated by the parametric model establishment method is used to simulate the filtration process. The simulated calculation value of the filtration efficiency of the fiber filter medium shows a high consistency with the experimental measurement value. This shows that this method can accurately evaluate the filtration efficiency of electrospun nanofiber membranes, which has a practical reference value for predicting the particle capture performance of electrospun nanofiber membrane filters and can provide guidance for the development of electrospun nanofiber materials.