An investigation of the effect of vertical-fin location and area on low-speed lateral stability derivatives of a semitailless airplane model Page: 2 of 42
This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
ACA RM L51A10O
NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS
RESEARCH MEMORANDUM
AN INVESTIGATION OF THE EFFECT OF VERTICAL-FIN LOCATION
AND AREA ON LOW-SPEED LATERAL STABILITY DERIVATIVES
OF A SEMITAILLESS AIRPIANE MODEL
By Lewis R. Fisher and William H. Michael, Jr.
SUMMARY
The results of a low-speed wind-tunnel investigation to determine
the effects of vertical-fin location and area on the static and rotary
lateral stability characteristics of a semitailless airplane model
indicated that the contributions of the vertical fin to the stability
derivatives could be estimated with reasonable accuracy by simple
considerations in spite of the unusually short tail length and large
tail height of this configuration.
Although the differences in fin effectiveness are not large, for
comparable fin areas and equal tail lengths, fins located at the 86-
percent spanwise location are, in general, more satisfactory for
providing directional stability and damping in yaw than fins located at
the 43-percent spanwise location. In the low lift-coefficient region,
a single central fin provided more directional stability but less
damping in yaw than twin fins located at either outboard position. The
central fin has an advantage over the outboard fins in that the fin
effectiveness tends to increase slightly at high lift coefficients, while
the trend is for the outboard fins to suffer a decrease in effectiveness
in this lift-coefficient region.
Changes in vertical-fin arrangement had no appreciable effect on the
damping in roll but, in some cases, resulted in significant changes in
the yawing moment due to rolling.
The nature of the span loadings induced on the wing by the lift on
the fins in sideslip resulted in a-change of sign of the effective-
dihedral parameter with lateral movement of the fins. The increment to
the effective dihedral due to the vertical fins was negative at the
43-percent spanwise position and positive at the 86-percent position.
Upcoming Pages
Here’s what’s next.
Search Inside
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Fisher, Lewis R. & Michael, William H., Jr. An investigation of the effect of vertical-fin location and area on low-speed lateral stability derivatives of a semitailless airplane model, report, March 7, 1951; (https://digital.library.unt.edu/ark:/67531/metadc58789/m1/2/: accessed March 30, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.