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Second coefficient of viscosity in airAcoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used. This analysis showed that the second coefficient of viscosity varied between 1900 and 20,000 times larger than the dynamic or first coefficient of viscosity over the temperature and humidity range of the data. In addition, the data showed that the molecular relaxation effects, which are responsible for the magnitude of the second coefficient of viscosity, place severe limits on the use of time-independent, thermodynamic equations of state. Compressible flows containing large streamwise velocity gradients, like shock waves, which cause significant changes in particle properties to occur during time intervals shorter than hundredths of seconds, must be modeled using dynamic equations of state. The dynamic model approach is described briefly.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Ash, Robert L.
(Old Dominion Univ. Norfolk, VA., United States)
Zuckerwar, Allan J.
(NASA Langley Research Center Hampton, VA., United States)
Zheng, Zhonquan
(Old Dominion Univ. Norfolk, VA., United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1991
Subject Category
Inorganic And Physical Chemistry
Report/Patent Number
NAS 1.26:187783
Accession Number
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.
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