The present study focuses on the design and performance evaluation of a rectangular mixed compression intake for ducted rocket ramjet applications. For the theoretical design stage, a 1D optimization criterion has been used to fix the ramp angles for theoretical maximum total pressure recovery (TPR), at on-design M 2.9 (shock-on-lip). Two different ramp designs (two and three ramps) have been considered for optimization, to find their effect on the overall performance. The throat height has been fixed using the practical self-starting contraction ratio (CR), (i) for the on-design Mach number of 2.9 and (ii) for the low off-design Mach number of 2. The throat length used is about six times the throat height for the required supercritical margin as well as to contain the shock train and the subsonic diffuser divergence angle is about 6°. The viscous flow field has been obtained by solving Favre averaged Navier-Stokes (FANS) equations with two-equation SST k-ω model. The analysis shows that, for the two-ramp and three-ramp design with self-starting contraction ratio at M 2.9, the on-design critical TPR is 0.645 and 0.67, and the critical mass flow ratio (MFR) is 1 and 0.99, respectively. The performance at low off-design M 2 shows, the MFR of both designs reduces to 0.51 and 0.47, respectively, and improves to a value of 0.6 for the two-ramp configuration with self-starting CR at M 2. This indicates that the two-ramp design has a better low off-design Mach number performance.
Theoretical Design and Performance Evaluation of a Two-Ramp and a Three-Ramp Rectangular Mixed Compression Intake in the Mach Range of 2–4
Lect.Notes Mechanical Engineering
Design and Development of Aerospace Vehicles and Propulsion Systems ; Chapter : 10 ; 143-166
2021-03-19
24 pages
Article/Chapter (Book)
Electronic Resource
English
Mach 8 Testing of a Scramjet Engine with Ramp Compression
British Library Conference Proceedings | 2000
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