472
B. Arizmendi et al.
Fig. 15.5 Icing tunnel tests
on the NASA Lewis research
center. Tests of a reduced
model of a commuter aircraft.
Source: NASA
including airspeed, angle of attack, LWC, or MVD. Some of these uncertainties
could be reduced by further testing and retrofitting the tunnel design such as the
study conducted by Arrington [47] to improve the flow quality. In addition, effects
of the blockage on the icing tunnel, i.e., ratio of the airfoil chord to the test-section
height and the wall-wing interaction are found to increase the uncertainties of the
reproduced shapes [48].
A common practice to study the uncertainties in the icing wind tunnels is the
performance of repeatibility tests. The objective of the tests was to assess the quality
and robustness of the results. Repeatability over several runs of a test is defined as
the maximum percent deviation found from the mean value of the results. In diverse
research, the repeatability of icing tests ranges between 10 and 30% [49]. The
repeatability of the spray clouds was found as the main source of uncertainty [50].
The development and implementation of sophisticated mathematical tools which
have been presented throughout the pages of this book could help handling these
large uncertainties.
15.2.5.3 State-of-the-Art Computational Ice Accretion Methods
In the past, various numerical methods were developed to simulate ice accretion
on aircraft. Tran et al. [22] developed a numerical method to help aid in predicting
ice modification on airfoils including the thermodynamic effects. Using a Eulerian
approach for flow theory Cao et al. [51] described a numerical simulation method
in which predicting the ice accretion on three-dimensional fixed wings. While
researching icing models, Tsao and Rothmayer [52] investigated the formation
of surface roughness on the surface of airfoils through the stability analysis of
air/liquid and water/ice on substrate interfaces. Fortin et al. [53] created a new
analytical model for the calculation of roughness heights and a new geometric ice
B. Arizmendi et al.
Fig. 15.5 Icing tunnel tests
on the NASA Lewis research
center. Tests of a reduced
model of a commuter aircraft.
Source: NASA
including airspeed, angle of attack, LWC, or MVD. Some of these uncertainties
could be reduced by further testing and retrofitting the tunnel design such as the
study conducted by Arrington [47] to improve the flow quality. In addition, effects
of the blockage on the icing tunnel, i.e., ratio of the airfoil chord to the test-section
height and the wall-wing interaction are found to increase the uncertainties of the
reproduced shapes [48].
A common practice to study the uncertainties in the icing wind tunnels is the
performance of repeatibility tests. The objective of the tests was to assess the quality
and robustness of the results. Repeatability over several runs of a test is defined as
the maximum percent deviation found from the mean value of the results. In diverse
research, the repeatability of icing tests ranges between 10 and 30% [49]. The
repeatability of the spray clouds was found as the main source of uncertainty [50].
The development and implementation of sophisticated mathematical tools which
have been presented throughout the pages of this book could help handling these
large uncertainties.
15.2.5.3 State-of-the-Art Computational Ice Accretion Methods
In the past, various numerical methods were developed to simulate ice accretion
on aircraft. Tran et al. [22] developed a numerical method to help aid in predicting
ice modification on airfoils including the thermodynamic effects. Using a Eulerian
approach for flow theory Cao et al. [51] described a numerical simulation method
in which predicting the ice accretion on three-dimensional fixed wings. While
researching icing models, Tsao and Rothmayer [52] investigated the formation
of surface roughness on the surface of airfoils through the stability analysis of
air/liquid and water/ice on substrate interfaces. Fortin et al. [53] created a new
analytical model for the calculation of roughness heights and a new geometric ice