Note: Descriptions are shown in the official language in which they were submitted.
The presen-t invention is concerned with fluid flow
concentrating devices and in one of its aspects with a ~1ind corlcen-
trating device in the form of a vortex generator of the -tornado-
type.
It is knownfrom United States patent No. ~,070,131 -to
provide a device in which atmospheric wind is admitted into a
vertically extending open ended structure which is spaced lrom the
ground or connected to a subterranean ram-air tunnel. The admitted
wind is directed against the interior curved surface of the s-truc-
ture and provides a vortex flow and khis flow provides a corres-
ponding low pressure core which draws the air into the bottom of
the structure to drive a horizontal turbine. Other fluid flow
devices of the prior art are to be seen in United States pa-tents
Nos. 4,236,866; 4,142,822; 4,269,563; 4,~60,325 and 1,519,447.
Other wind augmentation types of devices are also in experimental
use, these fall broadly into the categories of "duct augmentor
tubines" and "tip vane turbines". The devices of the prior art
have been useful for particular applications but are limited in
their scope of application.
The present invention seeks to provide a fluid flow
concentrator which will have a wide versatility of application.
According to the present invention there is provided a
~luid ~low concentrating device comprising a substantially hollow
body substantially closed at one end and open a~ the other, an
axially ex-tending vortex stabilizing column arranged substantially
centrally of the hollow body, the body having a fixed circumferen-
tial wall means co~lposed of a plurality of fixed spaced vanes and
a di~fuser channel located at the open end oE the wall means,
whereby fluid moving from the outside -the device subs-tantially
radially through the vanes -to the inslde of the body, creates a
vortex within the hollow body and a fluid 10w axially of -the body
throuyh the diffuser channel.
In a preferred form of the device the vanes are substan-
tially equally spaced circumferentially and maybe of aerofoil
cross-section.
In one preferred embodiment of the invention the vor-te~
stabili2ing column may extend -through -the diffuser channel. If
desired, the column may be provided with a plurality of brace
members extending radially outwardly of the column within the
substantially hollow body.
The vanes may conveniently be provided with trailing
edge fluid flow modifiers which may be flap-like elements.
In a preferred construction a turbine is mounted for
rotation, ln the direction opposite to the direction of rotation
of the vortex, centrally within the diffuser, about a vertical
axis. The blades of the turbine may conveniently b~ located
within the diffuser~
In one application of the device according to the
present invention the hollow body may be located on an airborne
craft with the open end of the body being normally directed in the
direction of the ground, in this application the fluid may be, at
least in part, a hot gas, a toroidal duct conveniently maybe
arranged in the craft adjacent to the diffuser channe~ so as to
blow the hot gas into the hollow body through the vanes which in
this instance would be hollow.
In another application of -the device, the hollow body
may be mounte~ externally a-t -the in-take of a je-t engine, the
circum-feren-tial wall means providing a pointed cone shape struc-
ture extending forwardly of -the engine in-take, point forward. In
this construction the vanes, may be -twis-ted and/or -tapered.
According to another application of the present inven-tion
the hollow body may be moun-ted on a marine vessel wi-th the open
end of the body being normally directed upwardly; convenien-tly a
turbine shaft may be provided within the body centrally and axially
thereof and may carry radially extending turbine blades within the
diffuser for rotation in a direction opposite to -the direc-tion of
rotation of the generated vortex, the end of the -turbine shaft
remote from the blades may be connected for, say, propulsion of
the vessel, for example by mechanical or electrical means.
The following is a description by way of example of
certain embodiments of the present invention reference being had
to the accompanying drawings in which:
Figure 1 is a schematic representation partly in section
of a fluid flow concentrating device;
Figure 2 is a plan view of the device of Figure l;
Figure 2a, i5 a detail of various vane cross-section
configurations;
Figure 2b is a schematic representation similar to
Figure 1 but including a ~urbine.
Figure 3 is a schematic representation, partially in
section of an application to augment the lift of an aircraft
wing;
-- 3 --
Figure 4 is a plan view in part sec-tion of -the device of
Figure 3;
Figure 5 i.s a schematic representation of a marine
application,
Figure 6 is a schematic representation of an ~ppli-
cation as an intake augmentor and a -thrust augmentor for a je-t
engine; and
Figure 7 is a schematic representation of the application
of the device in accordance with Figures 3 and 6 to an aircraft.
Referring now to drawings in which like parts have been
given like numbers. A fluid flow concentrating device 10 comprises
a substantially hollow body 11 closed at one end 12 and open a-t
the other 13. The body has a fixed circumferential wall 14 com-
posed of a plurality of fixed substantially equally spaced vanes
1~ and a diffuser channel 18 located at the open end 13 of the
wall 14. As shown the vertical axis is normal to the direction of
fluid flow F and wherever practical, the portion of the device 10
will be selected so that its axis is normal to the fluid flow.
Fluid moving from outside the wall 14 through -the vanes 16 to the
inside of the body creates a vortex V within the hollow body 11
and a fluid flow axially of the body 11, outwardly through the
diffuser channel 180 A vortex stabili2ing column 20 may be
provided axially of the hollow body and centrally thereofO In
order to get highly efficient use of the vortex~ the vane angle
should preferably be about ~5 with the radius, further the ratio
of the overall height of the device to the minimum diame-ter of -the
diffuser should preferably be near uni-ty, as can be seen in Figure
1.
-- 4 --
. O
The vanes 16 may be of aerofoil cross-section as in
E~igure 2a or may be of other suitable shapes for example, as al 50
shown in Figure 2a. The vanes 16 may be provided with fluid flow
modifiers, as seen in Figure 2 as Elaps 22 hinged -to -the trailiny
edge of the vanes 16.
As seen in Figure 2 -the stabilizing column 20 may be
pro~ided wi-th a plurality of brace members 24 extending radially
outwardly from the column 20 within the hollow body and connected
at -the outer edges to -the diffuser 18.
In one preferred application, see Figure 2b, the augmen-
tor of Figure 1 is modified to incorporate a turbine 29 mounted on
a centrally located, axially extending, turbine shaft 30. Turbine
blades 31 are housed within the diffuser 18 and provide a particu-
larly safe and compact configuration. By placing the tubine 29
downstream of the vor-tex V the advantage is achieved that the
energy in the axial exhaust flow, ra-ther than in the vortex itself,
is used. The design of the turbine blades is selected in accor-
dance with accep~ed engineering proceedures, such that the turbine
blades 31 are driven in a direction opposite -to the direction of
rotation of the vortex V and thus the turbine does not diminish
the vortex V. The turbine shaft 30~ is supported inside the
diffuser 18 by bearing in hub 25 with brace members 24. The
opposite end of the shaft, is connected to a device for power
utilization say an electric generator located outside the closed
end 12.
The fluid flow concen-trating device 10 as described with
respect to Figures 1, 2, 2a, and 2b is suitable for use in a wide
variety of applications. It can be used as a device to augment
wind veloci-tes, which may in turn be used to drive an air turbine
or it may be used hydraulically, say, in a tidal si-tua-tion, or low-
head hydro power generation. In a tidal si-tua-tion -the incominy
tide F would act to enter the vanes 16 in the same fashion as a
wind and create a whirlpool which could be used in an~ sui-table
fashion, for example to drive a hydraulic turbine in opposi-te
direc-tion to the whirlpool.
Turning now to Figure 3 which shows, together wi-th
Figure 4, the arrangement of the device in an airborne craft as a
lift augmentor for the wing of an aircraft. Here the concentrating
device 10 is mounted on top o~ the aircraft wing 35 with the
closed end 12 o~ the body spaced from the upper sur~ace 36 of the
wing by the vanes 16. In this preferred configuration, the vanes
16 form a substantially frusto-concical structure, narrower at the
top then at the base. The vanes may be twisted and/or tapered.
The diffuser channel ]8 is arranged within the wing itself and
communicates with the underside 37 o~ the wing.
As the aircraft moves through the air, a wind ~ is
created and this passes through the vanes 16 and produces a vortex
V2 which provides a downwardly directed airflow to augment the
lift of the wing: The air entering the device 10 can be controlled
by means o~ trailing edge flaps in the vanes 16 as in Figure 2 0
If required, for say, a VTOL application, a toroidal shaped duct
38 is located around the diffuser channel 18 and is provided with
hot gases from the aircraft propulsion engines through a duct 39.
The hot gases entering the duct 38 from the duct 39, pass around
the duct 38 into the vanes 16, which in this configuratiOn are
hollow, and are blown through nozzles at the tralling edge of -the
vanes 16 (see arrows 40 in Figure 4) to produce the vortex in
the device 10. The resultant thrust from the hollo~ bod~ 11
through the diffuser 18 may be controlled by a but-terfly va:lve
42, suitably mounted in the difEuser 18 on the stabilizer column
20.
Figure 7 shows the arrangement of the lift augmentor
as seen in Figures 3 and 4, in an aircraft at 45, that is to say,
near the wing tips and generating trailing vortices which rotate
in the same sense as the wing tip trailing vortices.
Figure 5 shows the application of the device 10 as a
wind augmentor to drive a turbine 31, the shaft 30 of which is
connected to some suitable power takeoff, for example, an elec-
trical generator, which in turn can drive an electric motor to
propel the watercraftO
Figure 6 shows the application of the device 10 in two
fashions to a jet engine. The intake augmentor 50 is mounted
externally at the intake 51 of a jet engine and the circumferen-
tial wall 14 extends forwardly of the engine intake, the vanes
16 providing a conical configuration, closed at one end by
the point 54. In this instance, since the wall 14 is not
cylindrical, the vanes 16 advantageously may be twisted and/or
tapered. The air taken in through the vanes 16 creates a vortex
V3 and improves the efficiency of the engine intake, by
increasing the velocity of the intake air. The diffuser 1~ is
shaped so as to provide a smooth flow into the intake of the
engine. The cone shape of the augmentor 50 additionally
~, .
Sr~
inhibits bird ingestion.
At the exhaust end o the jet engine the engine bod~
itself provides the closed end 12 -to the device 10 arranged as
a thrust augmentor 60, vanes 16 conveniently being, as in the
case of the intake augmentor, twisted and/or tapered and once
again the diffuser 18 at the open end o~ the concentrator lO
provides Eor the escape of exhaust gases from the jet engine.
External air passing through the vanes 16 crea-tes a vortex V4
which improves the performance of the engine and this vortex
is stabili~ed by the jet flow itself. That is to say the
convergent mixing flow induced by the free jet on passing
through the augmentor 60 causes a reduction in pressure around
the jet thereby increasing the jet velocit~ and the jet thrust~
The subsequent increase of the mixing flow, strengthens the
axial vortex and produces a ring vortex 61 which further augments
the thrust. Yet a urther augmentation of the thrust results
from ~he increased entropy of the mixing flow by the hot jet
gases through convection and radiation.
In Figure 7 the fashion of mounting the devices of
Figure 6 on an aircraft is illustrated.
It will be understood that the thrust augmentor 60
could also be used to augment the thrust from a rocket engine
when operatin~ in the atmosphere in a manner similar to its
use with a jet engine.
