Scholarly Works, Aerospace and Ocean Engineering

Permanent URI for this collection

https://hdl.handle.net/10919/23164
Research articles, presentations, and other scholarship

Browse

Browsing Scholarly Works, Aerospace and Ocean Engineering by Subject "Absorption spectroscopy"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Practical aspects of implementing three-dimensional tomography inversion for volumetric flame imaging
    Cai, Weiwei; Li, Xuesong; Ma, Lin (Optical Society of America, 2013-11-01)
    Instantaneous three-dimensional (3D) measurements have been long desired to resolve the spatial structures of turbulent flows and flame. Previous efforts have demonstrated tomography as a promising technique to enable such measurements. To facilitate the practical application, this work investigated four practical aspects for implementing 3D tomographic under the context of volumetric combustion diagnostics. Both numerical simulations and controlled experiments were performed to study: (1) the termination criteria of the inversion algorithm; (2) the effects of regularization and the determination of the optimal regularization factor; (3) the effects of a number of views; and (4) the impact of the resolution of the projection measurements. The results obtained have illustrated the effects of these practical aspects on the accuracy and spatial resolution of volumetric tomography. Furthermore, all these aspects are related to the complexity and implementing cost (both hardware cost and computational cost). Therefore, the results obtained in this work are expected to be valuable for the design and implementation of practical 3D diagnostics. (C) 2013 Optical Society of America
  • Thumbnail Image
    Simultaneous measurements of multiple flow parameters for scramjet characterization using tunable diode-laser sensors
    Li, Fei; Yu, XiLong; Gu, Hongbin; Li, Zhi; Zhao, Yan; Ma, Lin; Chen, Lihong; Chang, Xinyu (Optical Society of America, 2011-12-01)
    This paper reports the simultaneous measurements of multiple flow parameters in a scramjet facility operating at a nominal Mach number of 2.5 using a sensing system based on tunable diode-laser absorption spectroscopy (TDLAS). The TDLAS system measures velocity, temperature, and water vapor partial pressure at three different locations of the scramjet: the inlet, the combustion region near the flame stabilization cavity, and the exit of the combustor. These measurements enable the determination of the variation of the Mach number and the combustion mode in the scramjet engine, which are critical for evaluating the combustion efficiency and optimizing engine performance. The results obtained in this work clearly demonstrated the applicability of TDLAS sensors in harsh and high-speed environments. The TDLAS system, due to its unique virtues, is expected to play an important role in the development of scramjet engines. (C) 2011 Optical Society of America