Study of inline-slot ejector diffuser under varying ambient conditions: A passive infrared suppression device for ships

• Autorzy: Singh L. , Singh S. N. , Sinha S. S.

Identyfikatory

DOI

10.12716/1001.14.02.28

• Języki publikacji: EN

Abstrakty

EN

Passive infrared (IR) suppression device, commonly known as ejector diffuser, is an integral part of the defence system of a ship. The definitive role of passive IR suppressor to counter the IR tracking and locking of the ship has made them indispensable for any combat marine. The gas turbine exhaust gases are the leading heat source on a ship. The exhaust temperature of the gases ranges between 650K-850K. At such temperatures, the ship can be easily detected by the enemy through IR imaging. The role of the ejector diffuser is to (i) lower the gas turbine exhaust gases temperature to the limits (< 450K) such that the IR locking of the marine can be avoided, and (ii) recover static pressure such that the engine performance of the gas turbine is not affected. Ejector diffuser has the ability to entrain ambient air and allow mixing it with the exhaust gases thereby, lowering the temperature of the exhaust gases. However, the mixed exhaust gases temperature depends on the ambient air temperature which under extreme conditions can fluctuate from 273K to 323K. This temperature range can affect the temperature characteristics of an ejector diffuser. The present study undertakes the effect of ambient temperature on the performance of inline-slot ejector diffuser. The ambient temperature (T0) has been varied in the range 273K ≤ T0 ≤ 323K in the step of 10K. It has been found that the mass entrainment increases (≈ 8%) as the ambient temperature decreases. The core temperature at the exit decreases, from 457.58 K to 417.75K, with a decrease in the ambient temperature. However, no significant changes in static pressure recovery.

Słowa kluczowe

EN

applications for navy; ejector diffuser; passive iInfrared suppression device; InfraRed (IR); IR imaging; IR locking; Shear Stress Transport (SST); Infrared Suppression System (IRSS)

• Wydawca: Faculty of Navigation, Gdynia Maritime University
• Czasopismo: TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
• Rocznik: 2020
• Tom: Vol. 14, no. 2
• Strony: 477--482
• Opis fizyczny: Bibliogr. 12 poz., rys., tab.

Twórcy

autor

Singh L.

• Indian Institute of Technology Delhi, New Delhi, India 

autor

Singh S. N.

• Indian Institute of Technology Delhi, New Delhi, India 

autor

Sinha S. S.

• Indian Institute of Technology Delhi, New Delhi, India

Bibliografia

• [1] AM Birk and D VanDam. Marine gas turbine infrared  signature  suppression:  Aerothermal  design  considerations.  International  Gas  Turbine  and  Aeroengine  Congress  and  Exposition,  pages  V002T03A009–V002T03A009–10, 1989. 
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• [3] Saibal Sen. Studies on Flow Characteristics of a Stepped  Conical  Diffuser  with  Passive  Suction.  PhD  thesis,  Department of Applied Mechanics, Indian Institute of  Technology Delhi, 2008. 
• [4] Parminder  Singh,  S  N  Singh,  and  V  Seshadri.  Experimental Investigations on Non‐Circular Ejector Air  Diffusers. 39th AIAA Fluid Dynamics Conference, page  4213, 2009. 
• [5] Parminder  Singh,  Sidh  Nath  Singh,  and  V  Seshadri.  Effect  of  number  of  slots  and  overlap  on  the  performance of non‐circular ejector air diffuser. In 43rd  AIAA Fluid Dynamics Conference, page 2729, 2013. 
• [6] Qi Chen. Performance of air‐air ejectors with multi‐ring  entraining  diffusers.  PhD  thesis,  Department  of  Mechanical  and  Materials  Engineering,  Queen’s  University, 2008. 
• [7] L Singh, SN Singh, and SS Sinha. Effect of slot‐guidance  and  slot‐area  on  air  entrainment  in  a  conical  ejector  diffuser  for  infrared  suppression.  Journal  of  Applied  Fluid Mechanics, 12(4):1303–1318, 2019. 
• [8] L  Singh,  SN  Singh,  and  SS  Sinha.  Effect  of  standoff  distance and area ratio on the performance of circular  exhaust  ejector  using  computational  fluid  dynamics.  Proc. IMechE, Part G: Journal of Aerospace Engineering,  232(15):2821–2832, 2018. 
• [9] A  Maqsood.  A  study  of  subsonic  air‐air  ejector  with  short  bent  mixing  tube.  PhD  thesis,  Department  of  Mechanical  and  Materials  Engineering,  Queen’s  University at Kingston, Canada, 2008. 
• [10] Florian  R  Menter.  Two‐equation  eddy‐  viscosity  turbulence models for engineering applications. Journal  of AIAA, 32(8):1598‐1605, 1994. 
• [11] Simone  Crippa.  Improvement  of  unstructured  computational  fluid  dynamics  simulations  through  novel  mesh  generation  methodologies.  Journal  of  Aircraft, 48(3):1036–1044, 2011. 
• [12] W.  B.  Nicoll  and  B.  R.  Ramaprian.  Performance  of  conical diffusers with annular injection at inlet. Journal  of Fluids Engineering, 92(4):827–835, 1970.

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020)