# Numerical simulation of transient detonation structures in H _{2}-O _{2} mixtures in smooth pipe bends

## Abstract

While the detailed structure of detonations in low-pressure hydrogen-oxygen mixtures with high argon dilution has been fairly well analyzed by means of numerical simulation for two-dimensional rectangular channels, open questions remain for three space dimensions and non-rectangular geometries. In the present paper, we simulate the transient structural evolution as Chapman-Jouguet detonation waves in a perfectly stirred 2 H2+O2+7 Ar mixture at initial pressure 10kPa and room temperature propagate through smooth two-dimensional pipeline bends. The pipes have the constant width 8cm and encompass initially five regular detonation cells. For an unchanged inner radius of 15cm, we consider the bending angles 15, 30, 45, and 60 degree. The computations employ detailed chemical kinetics with 9 thermally perfect species and have been carried out with a massively parallel high-resolution finite volume code with temporal and spatial dynamic mesh adaptation. While we observe only changes in the detonation cell size for 15 degree, a partial decoupling of shock and reaction front occurs in the expansion region for larger bend angles. For 45 and 60 degree, a violent transverse detonation wave reignites the failure region. It is found that the reignition wave itself exhibits an instationary triple point around which the maximal pressure and temperaturemore »

- Authors:

- ORNL

- Publication Date:

- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC)

- OSTI Identifier:
- 931741

- DOE Contract Number:
- AC05-00OR22725

- Resource Type:
- Conference

- Resource Relation:
- Conference: 21st Int. Colloquium on the Dynamics of Explosions and Reactive Systems, Poitiers, France, 20070723, 20070727

- Country of Publication:
- United States

- Language:
- English

- Subject:
- hydrogen-oxygen detonations; pipe bends; numerical methods; mesh adaptivity

### Citation Formats

```
Deiterding, Ralf.
```*Numerical simulation of transient detonation structures in H2-O2 mixtures in smooth pipe bends*. United States: N. p., 2007.
Web.

```
Deiterding, Ralf.
```*Numerical simulation of transient detonation structures in H2-O2 mixtures in smooth pipe bends*. United States.

```
Deiterding, Ralf. Mon .
"Numerical simulation of transient detonation structures in H2-O2 mixtures in smooth pipe bends". United States.
doi:.
```

```
@article{osti_931741,
```

title = {Numerical simulation of transient detonation structures in H2-O2 mixtures in smooth pipe bends},

author = {Deiterding, Ralf},

abstractNote = {While the detailed structure of detonations in low-pressure hydrogen-oxygen mixtures with high argon dilution has been fairly well analyzed by means of numerical simulation for two-dimensional rectangular channels, open questions remain for three space dimensions and non-rectangular geometries. In the present paper, we simulate the transient structural evolution as Chapman-Jouguet detonation waves in a perfectly stirred 2 H2+O2+7 Ar mixture at initial pressure 10kPa and room temperature propagate through smooth two-dimensional pipeline bends. The pipes have the constant width 8cm and encompass initially five regular detonation cells. For an unchanged inner radius of 15cm, we consider the bending angles 15, 30, 45, and 60 degree. The computations employ detailed chemical kinetics with 9 thermally perfect species and have been carried out with a massively parallel high-resolution finite volume code with temporal and spatial dynamic mesh adaptation. While we observe only changes in the detonation cell size for 15 degree, a partial decoupling of shock and reaction front occurs in the expansion region for larger bend angles. For 45 and 60 degree, a violent transverse detonation wave reignites the failure region. It is found that the reignition wave itself exhibits an instationary triple point around which the maximal pressure and temperature levels of the entire configuration do occur.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Mon Jan 01 00:00:00 EST 2007},

month = {Mon Jan 01 00:00:00 EST 2007}

}