Finite element simulation of nitrogen transformation and transport during hysteretic flow with air entrapment
A two-dimensional finite element model was used to predict multispecies transport and transformation of nitrogen accompanying unsaturated flow with hysteresis and air entrapment. Results show that under potential-type boundary conditions, hysteresis substantially influences transport predictions due largely to air entrapment effects. Nonhysteretic simulations using main wetting curve parameters corresponded much more closely to hysteretic results that those using main drainage relations. For contaminant introduction via buried constant strength line sources, hysteresis had little effect on predictions of N transport.