Shock tube test time limitation due to turbulentwall boundary layer

Mirels, Harold

doi:10.2514/3.2218

Cited by 205 publications

(61 citation statements)

References 9 publications

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“…4, 5, and 6. The interpretation error for the uncompensated CO-emission trace would be appreciable, but adjustment of the signal to account for the increasing T and P brings the inferred CO mole fraction to a straight line, as expected since the CO does not decompose at 1803 K. Similar compensation should also be done when analyzing IR emission data from other molecules such as CH 4 and N 2 0. When the mole fraction of the emitting species is not known, the measured dP/dt can be used to infer the correct I and T correction via Eqns.…”

Section: (13)mentioning

confidence: 99%

“…The nonuniform conditions upstream of the reflected shock wave were defined using the incident-shock attenuation theory of Petersen [19] and Mirels [3,4], and the perturbations between the reflected shock wave and the endwall were assumed to propagate along right-and left-running characteristics. The results of the model agree well with experiment; the calculated post-shock AT's are, in general, within a few K of the temperature increases obtained with the CO-emission technique.…”

Section: Discussionmentioning

confidence: 99%

“…Assuming the relationship between the pressure and temperature is isentropic (i.e., adiabatic and reversible), the isentropic change in pressure can be shown to be dP dt (4) Combining Eqns. 3 and 4, again invoking the approximation that P/P 0 « 1, the final expression for the temperature slope as a function of the measured change in ir emission is…”

Section: Measurement Proceduresmentioning

confidence: 99%

“…The formation and depletion of methyl was calculated using GRI-Mech 1.2 to model the decomposition of 100-ppm CH 4 in argon, and the initial conditions downstream of the reflected shock wave were assumed to be 1800 K and 100 atm. A temperature increase of d(T/T 0 )/dt = 30.5 s"…”

Section: (13)mentioning

confidence: 99%

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Nonideal Effects Behind Reflected Shock Waves in a High-Pressure Shock Tube

Mathieu¹,

Hanson²

1999

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044REPORT Public reporting burden for this collection ot information is estimated to average 1 hour per response, including the time for review ng instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comment regarding this burden estimates or any aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and Shock tubes often experience temperature and pressure nonuniformities behind the reflected shock wave that cannot be neglected in chemical kinetics experiments. Because of increased viscous effects, smaller tube diameters, and nonideal shock formation, the reflected-shock nonidealities tend to be greater in higher-pressure shock tubes. Since the increase in test temperature (AT 5 ) is the most significant parameter for chemical kinetics, experiments were performed in the Stanford High Pressure Shock Tube using infrared emission from a known amount of CO in Argon. From the measured change in vibrationally equilibrated CO emission with time, the corresponding dT 5 /dt (or AT5 for a known time interval) of the mixture was inferred assuming an isentropic relationship between post-shock temperature and pressure changes. For a range of representative conditions in Argon (20-530 Atm, 1240-1900, the test temperature 2 cm from the endwall increased 3-8 K after 100 )J,s and 15-40 K after 500 u,s, depending on the initial conditions. Separate pressure measurements using a shielded piezoelectric transducer confirmed the isentropic assumption. An analytical model of the reflected-shock gas dynamics was also developed. The measured incident-shock axial velocity profile and a model of the boundary layer growth provide the upstream boundary conditions needed to define the properties behind the moving reflected shock. The calculated AT 5 's agree well with those obtained from experiment. The analytical model was used to estimate the effects of temperature and pressure nonuniformities on typical chemical kinetics measurements. When the kinetics are fast and occur in less than 300 |is, the temperature increase is typically negligible, although some correction is suggested for kinetics experiments lasting longer than 500 (xs. The temperature increase, however, has a negligible impact on the measured absorption profiles of OH and CH 3 when using laser absorption diagnostics at 306 and 216 nm, respectively, validating the use of a constant absorption coefficient. Infrared emission experiments are more sensitive to temperature and pressure changes, so T 5 nonuniformities should be taken into account when interpreting IR-emission data. NONIDEAL EFFECTS BEHIND REFLECTED SHOCK WAVES IN A HIGH-PRESSURE SHOCK TUBEEric L. Petersen f and Ronald K. Hanson AbstractShock tubes often experience temperature and pressure nonuniformities behind the reflecte...

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Section: (13)mentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Measurement Proceduresmentioning

confidence: 99%

Section: (13)mentioning

confidence: 99%

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Nonideal Effects Behind Reflected Shock Waves in a High-Pressure Shock Tube

Mathieu¹,

Hanson²

1999

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“…Mirels [9] performed an analysis to estimate shock tube test time limitations due to turbulent boundary layers. Continuity and turbulent boundary layer theory are used, and the development of the boundary layer is allowed to influence the freestream conditions.…”

Section: Boundary Layermentioning

confidence: 99%

Development of a Single-Stage Implosion-Driven Hypervelocity Launcher

Szirti¹,

Loiseau²,

Batchelor³

et al. 2008

AIP Conference Proceedings

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Complex Internal Compressible Flows

Kontis

Jagadeesh

Rao

2010

Encyclopedia of Aerospace Engineering

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The control volume approach, if appropriately applied, can yield information on the dependencies among various variables on compressible flow systems, which is very useful for parametric studies. The complex internal compressible flows presented here fall into the following categories: steady flows through variable area ducts with and without heat addition and friction, nozzle starting and choking, shock trains, shock tubes, and unsteady flows inside angled‐bend ducts. Ram/Scram jet engines and ejectors are described, as they are representative examples of complex flow systems.

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Shock tube test time limitation due to turbulentwall boundary layer

Cited by 205 publications

References 9 publications

Nonideal Effects Behind Reflected Shock Waves in a High-Pressure Shock Tube

Nonideal Effects Behind Reflected Shock Waves in a High-Pressure Shock Tube

Development of a Single-Stage Implosion-Driven Hypervelocity Launcher

Complex Internal Compressible Flows

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