High-Resolution N2 CARS Measurements of Pressure, Temperature, and Density Using a Modeless Dye Laser

Abstract

In this study, high-resolution N 2 CARS measurements have been made using a modeless dye laser as the Stokes beam source to reduce the presence of mode noise. Along with this modification to the CARS technique, a new spectra fitting procedure was developed to avoid a starting-point bias in the leastsquares fitting results. Time-averaged and single-shot measurements of pressure were made in a static pressure vessel over the range of 0.1 to 4.0 atm to test the pressure sensitivity of the technique. In addition, the precision of single-shot measurements in the pressure vessel is indicative of the baseline pressurefluctuation detection limit of the system. The precision uncertainty of the measurements was studied to investigate the possibility of making property fluctuation measurements in high-speed flows. Centerline measurements of pressure and temperature in an underexpanded jet (M j = 1.85) were also used to determine the performance of the technique in a compressible flowfield. Improvements in accuracy for time-averaged and single-shot mean measurements and increased precision were found for pressure levels above 1.0 atm. For the subatmospheric pressure levels that are important in high-speed flows, the results indicated that the current method is incapable of making fluctuation measurements due to limited precision. Nevertheless, the increased precision above 1.0 atm indicates that fluctuation measurements may be possible with further modifications.

3D transient CFD simulation of an in-vessel Loss-Of-Coolant Accident in the EU DEMO fusion reactor

“…The model presented in Section III.B is verified here against another published model [34] and validated against experimental data also published [35], [36].…”

“…Therefore, a further step in the validation is undertaken and described below. Experimental results for this setup are available [35], [36], concerning, for example, the pressure profile across the first Mach disk. The profile of the static pressure computed with STAR-CCM+ shows a good agreement with the experimental data and with the simulation results of [34], see Figure 14(a).…”

Numerical Methods for Compressible Multiphase Flow with Sodium-Water Chemical Reaction

“…The pressurized air goes into the region from the inlet boundary simulating the nozzle exit with 5 mm radius. The stagnation pressure p 0 and temperature T 0 of the air was set to 0.617 MPa and 20 °C as with the experimental condition by Kuehner et al (4) or Woodmansee et al (5) . The air at the inlet boundary is in the critical state.…”

“…The numerical analysis of the three-dimensional underexpanded air jet in the air is firstly presented to confirm adequacy of the governing equations and the solution method considering compressibility. Kuehner et al (4) and Woodmansee et al (5) measured the profile of the pressure along the centerline of the underexpanded air jet in the air by using the coherent anti-Stokes Raman scattering (CARS) technique. The calculated pressure was compared to the experimental data.…”

Application of unstructured mesh-based numerical method to sodium-water reaction phenomenon analysis code SERAPHIM

“…4 Numerical results of underexpanded air jet in air. 張噴流の挙動を正しく再現している． 図 5 に同解析結果における噴流中心軸上の圧力分布を実験データ (Kuehner et al, 2002, Woodmansee, 1999と比較して示す．実験データは，噴出口から離れるに従い圧力は徐々に減少し，マッ ハディスクの存在位置で急峻に上昇する様子を示しているが，解析結果はこれを良好に再現している． Vol. 10 (1972), pp.…”