An Experimental Investigation of the Normal Acceleration of an Airplane Model in a Gust (open access)

An Experimental Investigation of the Normal Acceleration of an Airplane Model in a Gust

Note presenting an investigation in the gust tunnel to determine the influence of airplane wing loading, forward velocity, wing plan form, and the fuselage on the reaction of the airplane to a known gust. Tests were made for four values of gust velocity and for two gust gradients, specifically the sharp-edge gust and a gust rising linearly to full strength in a distance of several chord lengths.
Date: May 1939
Creator: Donely, Philip
System: The UNT Digital Library
A semi-graphical method for analyzing strains measured on three or four gage lines intersecting at 45 degrees (open access)

A semi-graphical method for analyzing strains measured on three or four gage lines intersecting at 45 degrees

Report presenting a method for analyzing strains measured on three or four gage lines intersecting at 45 degrees, which helps determine the state of stress at a point on a plane. An equation for adjustment factor and a master curve is provided, which can be memorized and easily used in the future.
Date: May 1939
Creator: Hill, H. N.
System: The UNT Digital Library
A simplified method for the calculation of airfoil pressure distribution (open access)

A simplified method for the calculation of airfoil pressure distribution

From Summary: "A method is presented for the rapid calculation of the pressure distribution over an airfoil section when the normal-force distribution and the pressure distribution over the "base profile" (i.e., the profile of the same airfoil were the camber line straight and the resulting airfoil at zero angle of attack) are known. This note is intended as a supplement to N.A.C.A. Report Nos. 631 and 634 wherein methods are presented for the calculation of the normal-force distribution over plain and flapped airfoils, respectively, but not of the pressures on the individual surfaces. Base-profile pressure-coefficient distributions for the usual N.A.C.A. family of airfoils, which are also suitable for several other commonly employed airfoils, are included in tabular form. With these tabulated base-profile pressures and the computed normal-force distributions, pressure distributions adequate for most engineering purposes can be obtained."
Date: May 1939
Creator: Allen, H. Julian
System: The UNT Digital Library
Some Notes on the Numerical Solution of Shear-Lag and Mathematically Related Problemsq (open access)

Some Notes on the Numerical Solution of Shear-Lag and Mathematically Related Problemsq

"The analysis of box beams with shear deformation of the flanges can be reduced to the solution of a differential equation. The same equation is met in other problems of stress analysis. No analytical solutions of this equation can be given for practical cases, and numerical methods of evaluation must be used. Available methods are briefly discussed. Two numerical examples show the application of the step-by-step method of integration to shear-lag problems" (p. 1).
Date: May 1939
Creator: Kuhn, Paul
System: The UNT Digital Library
Wind-Tunnel Investigation of Ground Effect on Wings With Flaps (open access)

Wind-Tunnel Investigation of Ground Effect on Wings With Flaps

From Summary: "An investigation was conducted in the N.A.C.A. 7- by 10-foot wind tunnel to determine the effect of ground proximity on the aerodynamic characteristics of wings equipped with high-lift devices. A rectangular and a tapered wing were tested without flaps, with a split flap, and with a slotted flap. The ground was represented by a flat plate, completely spanning the tunnel and extending a considerable distance ahead and back of the model. The position of the plate was varied from one-half to three chord lengths below the wing. The results are presented in the form of curves of absolute coefficients, showing the effect of the ground on each wing arrangement."
Date: May 1939
Creator: Recant, Isidore G.
System: The UNT Digital Library