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C CD Nozzles for Jet Propulsion

Operational Characteristics of Isentropic C Nozzles. A converging passage designed to accelerate the a gas flow is considered for study.The concern here is with the effect of changes in the upstream and downstream pressures on the nature of the flow and on the mass flow rate through a nozzle.Fou

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C CD Nozzles for Jet Propulsion

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    1. C & CD Nozzles for Jet Propulsion P M V Subbarao Professor Mechanical Engineering Department

    2. Operational Characteristics of Isentropic C Nozzles A converging passage designed to accelerate the a gas flow is considered for study. The concern here is with the effect of changes in the upstream and downstream pressures on the nature of the flow and on the mass flow rate through a nozzle. Four different cases considered for analysis are: Converging nozzle with constant upstream conditions. Converging-diverging nozzle with constant upstream conditions. Converging nozzle with constant downstream conditions. Converging-diverging nozzle with constant downstream conditions.

    3. Pressure Distribution in Under Expanded Nozzle

    4. Variation of Mass Flow Rate in Exit Pressure

    5. Variation of in Exit Pressure

    6. Variation of in Mass Flow Rate

    7. Low Back Pressure Operation

    8. Frictional Adiabatic Flow in A Variable Area Duct

    10. The Real Nozzle for Sonic Flow It is impossible to get a sonic flow with real converging nozzle. The flow is always subsonic (transonic) at the throat. A compact real converging nozzle can produce transonic jet. A real nozzle for sonic exit is a CD Nozzle.

    11. Ideal Convergent-Divergent Nozzle Under Design Conditions

    13. Convergent-Divergent Nozzle with High Back Pressure When pb is very nearly the same as p0 the flow remains subsonic throughout. The flow in the nozzle is then similar to that in a venturi. The local pressure drops from p0 to a minimum value at the throat, pthroat , which is greater than p*. The local pressure increases from throat to exit plane of the nozzle. The pressure at the exit plate of the nozzle is equal to the back pressure. This trend will continue for a particular value of back pressure.

    14. Convergent-Divergent Nozzle with High Back Pressure

    15. Mass Flow Rate at Higher Back Pressures

    18. Variation of Mass Flow Rate in Exit Pressure

    19. Variation of in Mass Flow Rate

    20. Further Decrease the Back Pressure till the throat is just choked…. Define this back pressure as critical back pressure, pb.critical.

    23. Variation of in Exit Pressure

    24. Variation of in Throat Pressure

    25. Variation of in Mass Flow Rate

    26. What Next? What happens if back pressure is further reduced? Still the pressure at the exit plane is equal to the throat pressure? Further lower pressure at throat !?!?!

    29. Convergent-Divergent Nozzle Under Off-Design Conditions

    31. Moving Shock Towards Exit

    34. Flow Visualization Studies

    35. Design Back Pressure

    36. Steady Cruising Design Conditions

    37. Back Pressure Lower than the design conditions

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