Shock tube

About: Shock tube is a research topic. Over the lifetime, 6963 publications have been published within this topic receiving 99372 citations.

A Shock-tube Investigation of Ignition in Ethylene–Oxygen–Argon Mixtures

Abstract: The ignition of ethylene-oxygen mixtures highly diluted with argon was studied in a shock tube by monitoring the emission from CH* and C2* or OH*. The measurements covered the temperature range of 1400–2100 K at the C2H4/O2 ratios of 0.33–1.00. From the observation of the CH*, C2*, and OH* emissions, a mechanism for the production of chemiluminescent species upon ethylene oxidation was briefly discussed, and from the observation of the induction period of the CH* emission, the following equation was found:logτ_CH[O_2]=-11.45+27.5×10^3/4.58T in units of s mol l−1, the rate-determining step being C2H3+O2→C2H3O+O.

High sensitivity piezoelectric sensors using flexible PZT thick-film for shock tube pressure testing

Abstract: With excellent electromechanical performance and flexibility, piezoelectric lead zirconate titanate (PZT) thick-film fabricated by tape-casting processing has been considered as sensing element in pressure sensor design. The use of flexible PZT thick-film in sensors makes it possible to withstand relatively large deformation or install onto curved surfaces such as those in pipeline pressure sensing, human pulse or heart rate monitor. In this paper, the performance of PZT thick-film pressure sensors is investigated, unimorph structure of pressure sensor was designed and fabricated, and the relationship between generated voltage signals to applied pressures of the model has been analyzed theoretically. Blast wave pressure test was conducted using shock tube setup to test its sensing ability in response to air pressure loading. Different sized sensors were tested and showed nearly linear relationship to blast pressure in the experimental conditions. The voltage sensitivities of the sensor samples tested are several times higher than a commercial pressure sensor.

All-Speed Time-Accurate Underwater Projectile Calculations Using a Preconditioning Algorithm

Abstract: An algorithm based on the combination of time-derivative preconditioning strategies with low-diffusion upwinding methods is developed and applied to multiphase, compressible flows characteristic of underwater projectile motion Multiphase compressible flows are assumed to be in kinematic and thermodynamic equilibrium and are modeled using a homogeneous mixture formulation Compressibility effects in liquid-phase water are modeled using a temperature-adjusted Tait equation, and gaseous phases (water vapor and air) are treated as an ideal gas The algorithm is applied to subsonic and supersonic projectiles in water general multiphase shock tubes, and a high-speed water entry problem Low-speed solutions are presented and compared to experimental results for validation Solutions for high-subsonic and transonic projectile flows are compared to experimental imaging results and theoretical results Results are also presented for several multiphase shock tube calculations Finally, calculations are presented for a high-speed axisymmetric supercavitating projectile during the important water entry phase of flight

Computational analysis of dense gas shock tube flow

Abstract: Nonclassical phenomena associated with the classical dynamics of real gases in a conventional shock tube are studied. A TVD predictor-corrector (TVD-MacCormack) scheme with reflective endwall boundary conditions is used for the one-dimensional Euler equations to simulate the evolution of the wave field of a van der Waals gas. Depending upon the initial conditions of the gas, wave fields are produced that contain nonclassical phenomena such as expansion shocks, composite waves, splitting shocks, etc. In addition, the interactions of waves reflected from the endwalls produce both classical and nonclassical phenomena. Wave field evolution is depicted using plots of the flow variables at specific times and withx-t diagrams.