Numerical investigations of scarmjet unstart
Abstract/Contents
- Abstract
- Supersonic combusting ramjets (scramjets) have been envisioned as an economic means for long-range hypersonic delivery system and access to outer space. If strong disturbances such as those due to combustion occur in the engine, a failure mode called unstart could result. When unstart occurs, the mass flow rate through the engine inlet cannot be maintained, leading to loss-of-thrust and engine stall. Because the probability of unstart grows with increasing heat release from combustion, the danger of unstart is an important factor limiting the performance of scramjets. The present studies perform calculations of scramjet unstart in both cold and hot airflows based on Reynolds-averaged Navier-Stokes (RANS) turbulence closures. The flow solver is first validated against a Mach 5 experiment without combustion, aiming at establishing confidence in the unstart-prediction capability of the solver. Modifications to the solver are then proposed to improve its convergence rate to steady-state solutions and to provide tools for the analysis of unstart dynamics. Finally, the solution curve of a Mach 8 scramjet is calculated in a wide range of heat-release rates in conjunction with studies of the bifurcation structure of scramjet systems. We will also discuss linearized system dynamics that provide insight into a metric to forewarn unstart and unstart-mitigation mechanisms.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Jang, Ik |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering. |
| Primary advisor | Moin, Parviz |
| Thesis advisor | Moin, Parviz |
| Thesis advisor | Alonso, Juan José, 1968- |
| Thesis advisor | Lele, Sanjiva K. (Sanjiva Keshava), 1958- |
| Advisor | Alonso, Juan José, 1968- |
| Advisor | Lele, Sanjiva K. (Sanjiva Keshava), 1958- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Ik Jang. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Ik Jang
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...