In the present scenario, as there is considerable focus on environmental concerns, especially in air quality improvement, nanofibrous filters offer an effective, economical, and simple method for filtration applications including respiratory protection, industrial processes, combat heavy vehicle engine filtration etc. The presence of nanofibers can enhance the collection efficiency of particles in the range of most penetrating particle size (MPPS) and can achieve a minimal pressure drop due to the slip effect that happens at the surface of nanofibers. The heterogeneities in the filter structure lead to drastic changes in the filter media performance as it affects the gas flow path and the particle behaviour. An attempt was made to model nanofibrous filter media in a relatively straightforward 2-D array model to evaluate the filtration performance. The filter media heterogeneities are captured by the detailed representation of fiber size distribution which involves a thorough statistical analysis from the SEM micrographs. An algorithm based on a random approach was developed to create the representable geometry of nanofibrous filter media by analyzing the nanolayer and base media separately. The gas-particle flow through nanofibrous filter media has been modelled by Eulerian-Lagrangian CFD approach, incorporating the relevant particle collection mechanisms for the desired particle flow conditions. The simulated results of pressure drop and collection efficiency are compared with experimental data. The numerical model thus provides possibilities for further investigations in the performance of nanofibrous filter media.