Effect of Slot-Guidance and Slot-Area on Air Entrainment in a Conical
                        Ejector Diffuser for Infrared Suppression

Singh, L; Singh, Sumer; Sinha, Sawan Suman

doi:10.29252/jafm.12.04.29326

Cited by 14 publications

(2 citation statements)

References 52 publications

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“…Thus, design modifications to the slots themselves need to be examined and evaluated to see if it can lead to improved performance. Singh et al 28 have investigated ejectordiffuser with inline slots in a conical diffuser and have also provided guidance at the slots in form of curved plates. The authors found that higher mass entrainment takes place due to guidance at the slot.…”

Section: Introductionmentioning

confidence: 99%

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

Singh¹,

Singh²,

Sinha

2020

Proceedings of the Institution of Mechanical Engineers, Part G:

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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.

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Section: Introductionmentioning

confidence: 99%

“…Singh et al. 28 have investigated ejector-diffuser with inline slots in a conical diffuser and have also provided guidance at the slots in form of curved plates. The authors found that higher mass entrainment takes place due to guidance at the slot.…”

Section: Introductionmentioning

confidence: 99%