Engineering topics

Schrenk, Oskar

Publications and source records attributed to Schrenk, Oskar.

6 records

NASA NTRS1933

A simple method for increasing the lift of airplane wings by means of flaps

Aerodynamic considerations led us, not long ago, to investigate a device which seemed to promise a contribution to the problem of reducing the landing speed of an airplane. We have subsequently learned that similar devices had already been proposed and investigated by others, but it seems advisable, nevertheless, to report our results. The problem is to create, in landing, a region of turbulence on the lower side of the wing near the trailing edge by some obstacle to the air flow. The devices tested by us consisted of flaps of varying chord and position, the chord s being equal to the distance of the pivot from the trailing edge.

Gruschwitz, Eugen↗

NASA NTRS1931

Experiments with a wing from which the boundary layer is removed by suction

This report presents the results of the first investigation of the physical principle of preventing the streamline separation by removing the boundary layer. It was aeronautical, in that it dealt with airfoils, but the results are of a very general application.

Schrenk, Oskar↗

NASA NTRS1930

A possible method for preventing the autorotation of airplane wings

At the suggestion of Professor Betz, the following device was tested with the object of reducing the autorotational speed of airplane wings. The model of a normal wing with the Gottigen profile 420, 1 meter span and 0.2 meter chord was provided with a pair of symmetrical slots on the suction side, connected with each other inside the wing. The arrangement of the testing equipment and models are given and the effect of the slots can be seen in the experimental curves that are included.

Schrenk, Oskar↗

NASA NTRS1930

The boundary layer as a means of controlling the flow of liquids and gases

According to one of the main propositions of the boundary layer theory the scarcely noticeable boundary layer may, under certain conditions, have a decisive influence on the form of the external flow by causing it to separate from the wing surface. These phenomena are known to be caused by a kind of stagnation of the boundary layer at the point of separation. The present report deals with similar phenomena. It is important to note that usually the cause (external interference) directly affects only the layer close to the wall, while its indirect effect extends to a large portion of the external flow.

Schrenk, Oskar↗

NASA NTRS1929

Experiments with a Wing Model from which the Boundary Is Removed by Suction

The present report deals with a series of tests made for the purpose of improving flow conditions about wings by applying the suction principle (increase of the lift coefficient and reduction of the drag about very thick wing sections). Though not conclusive, the report contains interesting results.

BOUNDARY LAYER REMOVAL - SUCTION (SCHRENK)↗

NASA NTRS1926

Experiments with a Sphere from which the Boundary Layer Is Removed by Suction

The task of removing the boundary layer by suction consists in producing, in place of the ordinary flow with the formation of vortices, another kind of flow in which the vortices are eliminated by drawing small quantities of fluid from certain points on the surface into the interior of the body. The experiments with a sphere, which constitute the subject of this report, were made early in the present year .

AERODYNAMICS↗