Capturing and simulating combustion instabilities in afterburner, leading to screech, is very difficult. Carrying out the transient analysis requires large computational facilities and there is a limitation of considering the reverse effect of acoustics on flow and combustion. A novel method of carrying out steady-state CFD analysis followed by acoustic analysis, to capture the acoustic cavity modes for different afterburner models was considered for the study to predict the optimum afterburner. Eight afterburners were modelled, with different area ratios, nozzle angles and equivalence ratios. The numerical calculations had been performed, by using ANSYS® Fluent, with realizable k- ε model and SIMPLE algorithm by enabling energy equation. Kerosene (C12H23) was considered as fuel with virtual fuel injectors with species transport for modelling combustion and finite-rate/ eddy dissipation model for solving the multiple simultaneous chemical reactions. Maximum Mach number was observed for the model with an equivalence ratio of 0.58, area ratio of 5.2 and nozzle angle of 6o and with minimum O2 mass fraction of 0.144 and maximum CO2 mass fraction of 0.075 due to complete combustion. The computational results were imported into Actran™ for acoustic analysis. It is found that the 10-20 dB less mean square pressure values; with maximum transmission loss of 75.5 dB at 530 Hz, 70.7 Hz at 990 Hz; was observed for the afterburner model with equivalence ratio of 0.58, area ratio of 5.2 and nozzle angle of 6o, indicating the maximum absorption of acoustic energy and mitigation of screech instabilities for the designed inlet conditions.


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    Title :

    Computational Studies on Combustion Instabilities for Various Configurations of Afterburner


    Additional title:

    Lect.Notes Mechanical Engineering



    Conference:

    National Conference on IC Engines and Combustion ; 2019 ; Kurukshetra, India November 01, 2019 - November 04, 2019



    Publication date :

    2020-08-19


    Size :

    13 pages





    Type of media :

    Article/Chapter (Book)


    Type of material :

    Electronic Resource


    Language :

    English







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