Potential flow in engine valves Page: 17 of 29
This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
N.A.C.A. Technical Memorandum No. 343
200, since, from there down, a term appears which was neglected
in the calculation.
It is easily seen that the flow in the limiting cases is
in order. For large overlappings the angle is very small and
finally becomes a = 900, at m = . At m = 1 (i-.e., in the
case where the channel is wide open), it is easily seen from
the equations for m, that K = 1 and a = 900. In constant
overlappings, K also increases with increasing a, so that
a reaches its apparent maximum at K = 1. For positive over-
lappings, the matnum angle is amax = 140 in case IIb and
amax = 8o in IIa. Each overlapping attains a maximum angle
at K = 1.
The course of rn with negative overlapping is quite dif-
ferent from what it is with positive overlappings. The indi-
vidual curves alternately cross one another so that, with in-
creasing K, a first increases, reaches a maximum and then
sinks again to K = 1. As to whether such a flow actually ex-
ists, cannot be maintained without further investigation.
Since this somewhat resembles the behavior of a throttle valve,
but does not concern valve flows, it was not investigated
In what follows, the quantities in question were determined
for several overlappings. Since the valves in use show over-
lappings of m = 0-0.6, there were investigated: mn = 0; 0.05;
0.1; 0.2; 0.3; 0.6. The corresponding values of K, a, etc.,
are obtained in the following manner. In the m diagram, for
Here’s what’s next.
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.
Eck, Bruno. Potential flow in engine valves, report, December 1, 1925; (digital.library.unt.edu/ark:/67531/metadc65148/m1/17/: accessed August 22, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.