Journal ArticleDOI
Towards better uncertainty estimates for turbulence statistics
L. H. Benedict,Richard D. Gould +1 more
TLDR
In this article, the statistical uncertainty associated with the sampling of random processes such as those which occur in turbulence research are given, and formulas based on normal distribution assumptions and on any general distribution shape are given for means, variances, Reynolds stresses, correlation coefficients, homogeneous and mixed turbulent triple products and fourth order turbulence moments.Abstract:
Methods for calculating the statistical uncertainty associated with the sampling of random processes such as those which occur in turbulence research are given. In particular, formulas based on normal distribution assumptions and on any general distribution shape are given for means, variances, Reynolds stresses, correlation coefficients, homogeneous and mixed turbulent triple products and fourth order turbulence moments. In addition, two resampling algorithms, the “bootstrap” and “jackknife”, are presented and compared using actual turbulence data. The availability of these methods will allow turbulence data to be presented with statistical uncertainty error bars on all turbulence quantities.read more
Citations
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Journal ArticleDOI
A strategy for quality and uncertainty assessment of long-term eddy-covariance measurements
Matthias Mauder,Matthias Cuntz,Clemens Drüe,Alexander Graf,Corinna Rebmann,Hans Peter Schmid,Marius Schmidt,Rainer Steinbrecher +7 more
TL;DR: In this paper, the authors present a comprehensive newly composed strategy emphasising tests on high-frequency raw data, expanding existing tests on statistics, fluxes and corrections, plus quantification of errors.
Journal ArticleDOI
PIV uncertainty propagation
TL;DR: In this article, the authors discussed the propagation of the instantaneous uncertainty of PIV measurements to statistical and instantaneous quantities of interest derived from the velocity field and derived the expression of the uncertainty of vorticity, velocity divergence, mean value and Reynolds stresses.
Journal ArticleDOI
Separation control with nanosecond-pulse-driven dielectric barrier discharge plasma actuators
TL;DR: In this article, the efficacy of dielectric barrier discharge (DBD) plasmas driven by high voltage (approximately 15 kV) repetitive nanosecond pulses approximately 100 ns FWHM) for flow separation control is investigated experimentally on an airfoil leading edge up to Re=1x106 (62 m/s).
Journal ArticleDOI
Aerodynamics of a Single Element Wing in Ground Effect
Jonathan Zerihan,Xin Zhang +1 more
TL;DR: In this article, the effect of ground proximity and flap setting has been quantified in terms of aerodynamic performance and off-surface flowfield characteristics of a cambered, double-element, high-lift wing operating in ground effect.
Journal ArticleDOI
Effects of initial conditions in decaying turbulence generated by passive grids
TL;DR: In this paper, the effects of initial conditions on grid turbulence are investigated for low to moderate Reynolds numbers, and the results show that these effects are primarily related to deviations between the turbulence produced in the wind tunnel and true decaying homogenous isotropic turbulence (HIT).
References
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Book
An introduction to the bootstrap
Bradley Efron,Robert Tibshirani +1 more
TL;DR: This article presents bootstrap methods for estimation, using simple arguments, with Minitab macros for implementing these methods, as well as some examples of how these methods could be used for estimation purposes.
Journal ArticleDOI
Bootstrap Methods: Another Look at the Jackknife
TL;DR: In this article, the authors discuss the problem of estimating the sampling distribution of a pre-specified random variable R(X, F) on the basis of the observed data x.
Journal ArticleDOI
Describing the Uncertainties in Experimental Results
TL;DR: The material presented in this paper covers the method of describing the uncertainties in an engineering experiment and the necessary background material, as well as a technique for numerically executing uncertainty analyses when computerized data interpretation is involved.
Book
RANDOM DATA Analysis and Measurement Procedures
TL;DR: A revised and expanded edition of this classic reference/text, covering the latest techniques for the analysis and measurement of stationary and nonstationary random data passing through physical systems, is presented in this article.