Ajay Krish

All Publications

• Laser absorption study of the N-2 + O -> NO plus N and NO plus O -> O-2 + N Zeldovich reactions in shock-heated N2O mixtures PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K. 2023; 35 (4)

  View details for DOI 10.1063/5.0147764

  View details for Web of Science ID 001003916300002

• Shock-Tube Measurements of Atomic Nitrogen Collisional Excitation in 8000-12000 K Partially Ionized Nitrogen-Argon Mixtures. The journal of physical chemistry. A Finch, P. M., Granowitz, Z. N., Streicher, J. W., Krish, A., Strand, C. L., Hanson, R. K. 2023

  Abstract

  We report on shock-tube experiments measuring the collisional excitation of atomic nitrogen using tunable diode laser absorption spectroscopy (TDLAS). Conditions behind the reflected shocks ranged from 8000 to 12000 K and 0.1 to 1.1 atm in mixtures of 1 or 2% molecular nitrogen (N2) in argon (Ar). Absorption from the transition between atomic nitrogen quantum states 4P to 4D at 868 nm was used to monitor the formation of electronically excited nitrogen. Population measurements of the 4P state were made at a rate of 50 kHz. In connection with these measurements, a multitemperature kinetic mechanism is proposed for nitrogen excitation. Measurements suggest a multistage process. In early test times, a period of induction due to N2 dissociation is followed by a rise via heavy particle excitation. The dominant channel causing this excitation is believed to be N + N N(4P) + N with a measured forward rate constant of 3.65 * 10-18 exp(-119892/T) [m3/s]. As test time evolves, the excitation of 4P, referred to as N*, is subsequently interrupted and then resumes, as the kinetic environment becomes increasingly electron-dominated. The most impactful reactions of the mechanism are optimized to reduce the residual between simulations and the measurements. The measured N* populations indicate strong, though indirect, sensitivity to adjacent processes, including the excitation of metastable nitrogen, and ionization channels.

  View details for DOI 10.1021/acs.jpca.2c07839

  View details for PubMedID 36745871

• Application of Reflected Shock Wave Configuration to Validate Nonequilibrium Models of Reacting Air JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Gimelshein, S. F., Streicher, J. W., Krish, A., Hanson, R. K., Wysong, I. J. 2022

  View details for DOI 10.2514/1.T6630

  View details for Web of Science ID 000891162900001

• High-temperature vibrational relaxation and decomposition of shock-heated nitric oxide. I. Argon dilution from 2200 to 8700 K PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K. 2022; 34 (11)

  View details for DOI 10.1063/5.0109109

  View details for Web of Science ID 000882457400018

• High-temperature vibrational relaxation and decomposition of shock-heated nitric oxide: II. Nitrogen dilution from 1900 to 8200 K PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K. 2022; 34 (11)

  View details for DOI 10.1063/5.0122787

  View details for Web of Science ID 000882457400010

• Spectrally-resolved ultraviolet absorption measurements of shock-heated NO from 2000 K to 6000 K for the development of a two-color rotational temperature diagnostic JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER Krish, A., Streicher, J. W., Hanson, R. K. 2022; 280

  View details for DOI 10.1016/j.jqsrt.2022.108073

  View details for Web of Science ID 000748572500001

• Spectrally-resolved absorption cross-section measurements of shock-heated O-2 for the development of a vibrational temperature diagnostic JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER Krish, A., Streicher, J. W., Hanson, R. K. 2021; 270

  View details for DOI 10.1016/j.jqsrt.2021.107704

  View details for Web of Science ID 000670398200011

• Coupled vibration-dissociation time-histories and rate measurements in shock-heated, nondilute O-2 and O-2-Ar mixtures from 6000 to 14000K PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K. 2021; 33 (5)

  View details for DOI 10.1063/5.0048059

  View details for Web of Science ID 000677502500006

• Vibrational relaxation time measurements in shock-heated oxygen and air from 2000 K to 9000 K using ultraviolet laser absorption PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K. 2020; 32 (8)

  View details for DOI 10.1063/5.0015890

  View details for Web of Science ID 000559819800001

• Shock-tube measurements of coupled vibration-dissociation time-histories and rate parameters in oxygen and argon mixtures from 5000 K to 10 000 K PHYSICS OF FLUIDS Streicher, J. W., Krish, A., Hanson, R. K., Hanquist, K. M., Chaudhry, R. S., Boyd, I. D. 2020; 32 (7)

  View details for DOI 10.1063/5.0012426

  View details for Web of Science ID 000547489500002

• Ultraviolet absorption cross-section measurements of shock-heated O-2 from 2,000-8,400 K using a tunable laser JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER Krish, A., Streicher, J. W., Hanson, R. K. 2020; 247

  View details for DOI 10.1016/j.jqsrt.2020.106959

  View details for Web of Science ID 000536179300015