An axi-symmetric shock-tube model has been developed to simulate the shock-wave propagation and reflection in both non-reactive and reactive flows. Simulations were performed for the full shock-tube geometry of the high-pressure shock tube facility at Texas A & M University. Computations were carried out in the CFD solver FLUENT based on the finite volume approach and the AUSM+ flux differencing scheme. Adaptive mesh refinement (AMR) algorithm was applied to the time-dependent flow fields to accurately capture and resolve the shock and contact discontinuities as well as the very fine scales associated with the viscous and reactive effects. A conjugate heat transfer model has been incorporated which enhanced the credibility of the simulations. The multi-dimensional, time-dependent numerical simulations resolved all of the relevant scales, ranging from the size of the system to the reaction zone scale. The robustness of the numerical model and the accuracy of the simulations were assessed through validation with the analytical ideal shock-tube theory and experimental data. The numerical method is first applied to the problem of axi-symmetric inviscid flow then viscous effects are incorporated through viscous modeling. The non-idealities in the shock tube have been investigated and quantified, notably the non-ideal transient behavior in the shock tube nozzle section, heat transfer effects from the hot gas to the shock tube side walls, the reflected shock/boundary layer interactions or what is known as bifurcation, and the contact surface/bifurcation interaction resulting into driver gas contamination. The non-reactive model is shown to be capable of accurately simulating the shock and expansion wave propagations and reflections as well as the flow non-uniformities behind the reflected shock wave. Both the inviscid and the viscous non-reactive models provided a baseline for the combustion model iii which involves elementary chemical reactions and requires the coupling of the chemistry with the flow fields adding to the complexity of the problem and thereby requiring tremendous computational resources. Combustion modeling focuses on the ignition process behind the reflected shock wave in undiluted and diluted Hydrogen test gas mixtures. Accurate representation of the Shock-tube reactive flow fields is more likely to be achieved by the means of the LES model in conjunction with the EDC model. The shock-tube CFD model developed herein provides valuable information to the interpretation of the shock-tube experimental data and to the understanding of the impact the facility-dependent non-idealities can have on the ignition delay time measurements.

This volume contains original, refereed worldwide contributions. They were prompted by presentations made at the ninth AMCTM Conference held in G teborg (Sweden) in June 2011 on the theme of advanced mathematical and computational tools in metrology and also, in the title of this book series, in testing. The themes in this volume reflect the importance of the mathematical, statistical and numerical tools and techniques in metrology and testing and, also in keeping the challenge promoted by the Metre Convention, to access a mutual recognition for the measurement standards.

This book presents a collection of the best papers from the Seventh Asian Joint Workshop on Thermophysics and Fluid Science (AJWTF7 2018), which was held in Trivandrum, India, in November 2018. The papers highlight research outputs from India, China, Japan, Korea and Bangladesh, and many of them report on collaborative efforts by researchers from these countries. The topics covered include Aero-Acoustics, Aerodynamics, Aerospace Engineering, Bio-Fluidics, Combustion, Flow Measurement, Control and Instrumentation, Fluid Dynamics, Heat and Mass Transfer, Thermodynamics, Mixing and Chemically Reacting Flows, Multiphase Flows, Micro/Nano Flows, Noise/NOx/SOx Reduction, Propulsion, Transonic and Supersonic Flows, and Turbomachinery. The book is one of the first on the topic to gather contributions from some of the leading countries in Asia. Given its scope, it will benefit researchers and students working on research problems in the thermal and fluid sciences.

The U.S. Army Research Laboratory and the Centre d'Etudes de Gramat, France, executed a cooperative study in which the time dependent flow fields in Le Simulateur de Souffle a Grand Gabarit (SSGG) large blast simulator were examined. The flow characteristics of static and stagnation overpressure were measured at two longitudinal positions in the expansion tunnel of the simulator. Instrumentation rakes were designed and fabricated to support a total of 19 pairs of static and stagnation pressure transducers that were distributed across the expansion tunnel cross section at each of the longitudinal positions. Flow measurements were recorded for eight shots with peak static overpressure levels between 20 kPa and 120 kPa. The measured data were used to assess the flow uniformity and distribution at each of the longitudinal measurement positions in the simulator. A finite difference Euler equation solver and a finite volume Navier Stokes equation solver were employed in a set of detailed, three dimensional (3-D) fluid dynamics calculations that were performed to match the test conditions. The 3-D computational results are compared to the experimental data to further examine the time dependent flow characteristics and to validate the fluid dynamics codes for future blast studies.

The nonlinear characteristic differential equations applicable to a quasi-one-dimensional unsteady channel flow with friction and heat transfer are linearized and integrated in functional form for the particular study of small perturbations from ideal shock-tube flows. If the equivalence of unsteady- and steady-flow boundary layers is assumed, the problem of determining the perturbation in the unsteady flow reduces to an evaluation of the drag of a flat plate in the equivalent steady flow.

The current capabilities of kinetic modeling of hydrocarbon oxidation in shock waves are discussed. The influence of molecular size and structure on ignition delay times are stressed. The n-paraffin fuels from CH4 to n-C5H12 are examined under shock tube conditions, as well as the branched chain fuel isobutane, and the computed results are compared with available experimental data. The modeling results show that it is important in the reaction mechanism to distinguish between abstraction of primary, secondary and tertiary H atom sites from the fuel molecule. This is due to the fact that both the rates and the product distributions of the subsequent alkyl radical decomposition reactions depend on which H atoms were abstracted. Applications of the reaction mechanisms to shock tube problems and to other practical problems such as engine knock are discussed.