Effect of Reynolds number and slot guidance on passive infrared suppression device

Singh, L; Singh, Santokh; Sinha, Sawan Suman

doi:10.1016/j.ast.2020.105732

Cited by 25 publications

(11 citation statements)

References 26 publications

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“…The experimental setup is depicted in Figure 7(a), whereas Figure 7(b) shows the actual setup. Further details of the experimental setup are available in Singh et al 32 Figure 7(c) highlights the planes where the experimental results are obtained.…”

Section: Validation Of Cfd Methodologymentioning

confidence: 99%

“…where m in is the inlet mass flow rate and m je is the mass entrained through the j th slot. 32 Cumulative mass entrainment ratio (/). It is defined as the ratio of total mass entrained through the slots to the mass inlet flow rate (equation ( 15)):…”

Section: Performance Indicatorsmentioning

confidence: 99%

“…where N is the total number of slots. 32 Normalized temperature parameter (w). It is the ratio of the local temperature to the temperature at the nozzle exit (equation ( 16)):…”

Section: Performance Indicatorsmentioning

confidence: 99%

“…where T, T 0 , T g are the local, ambient and nozzle exit temperatures, respectively. 32 Pressure recovery coefficient (Cp). It is the ratio of the differential static pressure to the inlet dynamic pressure.…”

Section: Performance Indicatorsmentioning

confidence: 99%

“…It is the ratio of entrained mass from a given slot to the inlet mass flow rate (equation (14)):where m in is the inlet mass flow rate and m je is the mass entrained through the j th slot. 32…”

Section: Plan Of Studymentioning

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: Validation Of Cfd Methodologymentioning

confidence: 99%

Section: Performance Indicatorsmentioning

confidence: 99%

“…where N is the total number of slots. 32 Normalized temperature parameter (w). It is the ratio of the local temperature to the temperature at the nozzle exit (equation ( 16)):…”

Section: Performance Indicatorsmentioning

confidence: 99%

Section: Performance Indicatorsmentioning

confidence: 99%

Section: Plan Of Studymentioning

confidence: 99%

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