Experimental and Numerical Investigation on Humidity Distribution in an Environmental Chamber

Environmental chamber is widely used for testing the performance of the equipment with all kinds of natural ambient parameters. In this study, water droplet generated from ultrasonic humidifier is ascertained by laser diffraction measurement technology. The accurate droplet size and distribution is offered to CFD simulation as the initial condition. Humidity distribution with different initial conditions is studied by both experiment and CFD simulation. Comparisons show that the proposed CFD method can provide reliable results in simulation on the humidity distribution. The numerical and experimental results indicate that as the increase of inlet temperature, fluctuation of relative humidity (RH) at each point decrease with the time. Under the inlet condition with low-humidity, the deviation of average RH is decrease with inlet temperature. On the other hand, under the high-humidity condition, the difference of average RH is getting larger with the increase of inlet temperature. Compared with the mean value, the fluctuation of the humidity is big but the RH at measuring points is close to the inlet RH value under the inlet condition with low humidity.