Enhancement of air entrainment in ejector-diffuser using plate guidance at slots to reduce infrared emission

Ejector-diffuser reduces infrared emissions and are installed in combat aircraft to counter the threat of heat-seeking missile. The specific role of an ejector-diffuser is to reduce the heat emissions without substantially affecting the engine performance. The present study investigates a new design of ejector-diffuser wherein straight-plates and hybrid-straight-plates are installed at each slot for improving the ejector-diffuser performance. The evaluation criteria of an ejector-diffuser is specified in terms of air entrainment through the slots, thermal characteristics, and recovery of pressure. This work is carried out in two stages. In the first part, the orientation of the plate at the slot is investigated by varying the angle between the slot and diffuser axis over the range [Formula: see text]. The overall mass entrainment increases from 2.88 to 4.04 with the increase in plate angle. Further, the thermal characteristics also improves with increase in plate angle, but the pressure recovery decreases from 0.701 to 0.155. In the second part, the straight-plate at the slots are partially/fully replaced by hybrid-plate. Two configurations are proposed by first introducing a hybrid-plate at the first slot and straight-plate at the other slots, and subsequently by introducing hybrid-plate at all the slots. It is found that the pressure recovery in both the cases shows a significant improvement compared to the straight-plate case, the value being close to 0.75 for both the cases. However, the cumulative mass entrained by the first configuration of the hybrid-plate is better than the second configuration and is similar to the straight-plate guidance of 28°. Thus, the current study proposes an IRSS device having the hybrid-plate at the first slot and the straight-plate guidance at the remaining slots which reduces infrared emissions with minimum loading on the engine.

Covid-19 Virus Sterilization Oven Based on Combination Between Ultraviolet and Infrared Emissions

The world is countering an unexpected wide spread of Covid-19 virus. Among the procedures used to prevent spreading the virus are classical and modern sterilization methods. In this paper, we combine the use of ultraviolet emissions, as a modern method, with the infrared emissions that generates high temperature, as a classical method, to design and implement a sterilization oven. Ultraviolet emissions have the ability to destroy the RNA of the virus while the infrared emissions destroy the virus membrane. Test was performed on indicators contains +ve gram rod bacteria which is stronger than the Covid-19 virus in high temperature and UV emission tolerant. Results showed that the UV emissions killed the microorganism in 15 minutes. However, combination between the UV and IR emissions in a sterilization oven succeeded to kill the under test microorganism in five minutes. The combination between the two sources of emission guarantees an effective sterilization process against bacteria, fungus, and viruses. Moreover, it speeds up the sterilization process time.