Title of Invention

"FLOW STRAIGHTENER-THROTTLE FOR FAN TESTING RIG"

Abstract

The present invention pertains to a flow straightener- throttle for a fan testing rig consists of a plate with at least one hole having an air tight connection with an array of tubes at one end which in turn having an air tight connection with another plate with holes at other end, for throttling and straightening the flow of the fluid, and producing the hydrodynamic entry region for laminar flow of the fluid (air) in a duct. The plate may be circular or any other shape with different matrices of holes. Different matrices of these holes in the plates of the flow straightener- throttle results vary area ratio up to 100 %. The area ratio may also vary by blocking holes.

Full Text

FIELD OF INVENTION The present invention pertains to "a flow straightener - throttle for a fan testing rig", in particular to the field of fan testing of radiator for a vehicle or an internal combustion engine and other applications where ever the fans are used for cooling Vehicles are operated in the most hostile environments especially in high ambient and dusty conditions. Hence it is very essential that the vehicle having internal combustion engines should have effective and efficient cooling systems to neutralize the effect of heat on the power pack and other accessories to give optimum efficiency. For efficient and effective functioning of the internal combustion engines the performance characteristics of the air flow systems, especially the radiators and cooling fans should have maximum effect. PRIOR ART For evaluation of performance characteristics of the cooling fan, the test setup manufactured as per the available standards having a conical type of throttle valve to control the flow rate at the upstream and flow straightener is available globally. Following are the drawbacks of prior art: 1. The air enters through the conical type of throttle valve, first gets mixed up and then gets deflected by the wall and then at where and at which point the flow will get straightened cannot be predicted exactly and depends upon the speed of the air. Hence the throttle valve at the upstream-generated additional turbulence itself and the measurements are carried out in the presence of turbulence instead of laminar flow condition considered ideal. 2. The area ratio is not more than 22.5%, because the perforated plate placed in between the throttle valve and the duct but it was claimed 100% because of the mere openings of the throttle valve to 100%. Hence there is a need for a device which overcomes the problems of the prior art. In order to convert the turbulent flow into a laminar one at the upstream itself, and to control the flow or to increase the area ratio up to 100%, a single device named "flow straightener - throttle" has been invented. This invented device "flow straightener - throttle" serves the functions of throttle valve, converts the turbulent flow into laminar, and ensures hydrodynamic entry region and flow straightening. In addition by introducing different configurations of "flow straightener -throttle" and by removing the existing throttle valve and flow straightener, the area ratio is increased up to 100% and hence the flow pattern is improved. OBJECTS OF THE INVENTION The primary object of the invention is to provide for enhancing heat exchanger air mass flow rate, and straightening the flow of air.. Another object of the invention is to substitute two separate devices namely the throttle valve and the flow straightener with a single device. Further object of the invention is to make a device which is simple in construction. Still further object of the invention is to reduce the power consumption. SUMMARY OF THE INVENTION The present invention relates to a "flow straightener - throttle for fan testing rig" wherein the flow straightener - throttle when used for testing, serves the functions of throttling, flow straightening and eliminating the turbulence in flow to a greater extent and thus ensuring the laminar flow. Two plates and an array of tubes are used in the flow straightener - throttle. One plate with holes having air tight connection is fixed at each end of an array of tubes. The different matrices of holes are provided in plates as well as in array of tubes for achieving area ratio up to 100% in place of 22.5% of the conventional test rigs and ensuring the hydrodynamic entry region. The flow straightener-throttle of the present invention the performance characteristics such as pressure drop, flow rate and power consumption are optimized at different speeds, at different hole area conditions by changing the plates of different matrices of holes. According to one of the embodiment of a flow straightener - throttle for a fan testing rig comprises a plate with at least one hole having an air tight connection with an array of tubes having at least one tube at one end which in turn is having an air tight connection with the corresponding identical holes in another plate at other end, for throttling and straightening the flow of the fluid, and producing the hydrodynamic entry region for laminar flow of a fluid or air in a duct. DESCRIPTION OF THE ACCOMPANYING DRAWINGS Now the invention will be described in detail with reference to the accompanying drawing in which: Fig. 1 illustrates the layout of the fan test rig according to the present invention. Fig. 2 illustrates the "flow straightener - throttle". Fig. 3 illustrates the particular embodiment of holes for the "flow straightener -throttle". Fig. 4 illustrates an embodiment of matrices of holes of a plate used in the "flow straightener - throttle" according to the present invention. Fig. 5 illustrates the another embodiment of matrices of holes of a plate used in the "flow straightener - throttle" according to the present invention. Fig. 6 illustrates still further embodiment of matrices of holes of a plate used in for the "flow straightener - throttle" according to the present invention. Fig. 7 illustrates the flow rate Vs pressure drop performance characteristics curves for different holes conditions for a particular fan. Fig. 8 illustrates the family of performance characteristics curves for different holes conditions for a particular fan. Fig. 9 illustrates he flow rate Vs power performance characteristics curves for different holes conditions for a particular fan. Fig. 10 illustrates the speed Vs head characteristics curves for different holes conditions for a particular fan. Fig. 11 illustrates the speed Vs flow rate characteristics curves for different holes conditions for a particular fan. Fig. 12 illustrates the speed Vs power characteristics curves for different holes conditions for a particular fan. DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE DRAWINGS According to the preferred embodiment of the present invention, a flow straightener -throttle for a fan testing rig comprises a plate (12) with at least one hole (13) having an air tight connection with an array of tubes (11) having at least one tube at one end which in turn is having an air tight connection with the corresponding identical holes in another plate at other end, for throttling and straightening the flow of the fluid, and producing the hydrodynamic entry region for laminar flow of a fluid or air in a duct (1). In another embodiment a flow straightener - throttle the said plate (12) may be of circular or any other shape (14) with plurality of holes. Still another embodiment a flow straightener - throttle the said plates (12) and the said array of tubes (11) may have different matrices of holes of identical or different diameters (16) to obtain area ratio up to 100% Still another embodiment a flow straightener - throttle the said plate may have one central hole in air tight connection with one tube or with out tube to obtain an area ratio up to 100% Still another embodiment a flow straightener - throttle the some holes in plate selectively are blocked (17) to vary area ratio. In flow straightener-throttle a plate (11), which may be circular or any other shape. Total two plates (11) which may be circular or any other shape are required per array of tubes in the flow straightener - throttle", one plate with holes is fixed at each end of a array of tubes (12) through which the fluid is allowed to pass through as shown in figure 2. Similarly, as far as the area ratio is concerned, in the present invention area ratio up to 100 % is achieved by using different configurations of "flow straightener - throttle" by using a set of different matrices of plates and array of tubes at a time as shown in the figures 4 to 6. The different matrices of holes (13) in the plate (11) are such that these holes do not create any type of turbulence and ensures the laminar flow of the fluid in the device. Similarly the blocking of holes is done in such a way that this blocking (17) does not create any type of turbulence and ensures the laminar flow of fluid. This invention ensures the laminar flow by eliminating the turbulence to a greater extent. This was achieved by removing the throttle valve (either of conical or of butterfly type) and single configuration of flow straightener and mounting the invented "flow straightener - throttle" in the upstream side. In the fan testing rig , the fluid (air) is sucked through the flow straightener-throttle (8) at the entry point by the fan in the up stream side shown in Figure 1. This fluid (air) is passed through, the orifice (10), the duct (1), the reducer (2) and finally passed through the volute casing (3). The air enters the fan in the axial direction and leaves it in a radial or axial direction. In fig 1 a gear box (4) is attached to prime mover (5) to run the fan at different speed to suck air through the flow straightener - throttle (8). Accordingly the present invention is the first and only fan test set up having "flow straightener - throttle" comprising the functions of two separate devices namely: 1. Throttle valve for controlling the flow and 2. Flow straightener for straightening the flow. Experiments have been carried out with the existing test setup and with the invented test setup. It is evident from the experimental results that the flow rate with new test setup was improved to about 20%. This was achieved without any modification or improvement in the fan configuration. Or in other words the actual fan flow rate observed was more than 20% from the existing test setup. The following performance characteristics were evaluated with invented "flow straightener - throttle". 1. Flow rate of the cooling fan in nrVsec. 2. Power of the cooling fan in W at rated rpm, for the different flow rate. 3. Pressure drop Vs flow rate at various points across the airway for different holes conditions. The experimental results of the fans obtained with the "flow straightener - throttle" were very much at par with predicted results based on the standard fan laws. The pressure drop Vs the flow rate was plotted and the results obtained were very much satisfactory. It is also clear from the graph that as the speed increases the flow rate also increases and the curves are not deviating from the normal path. Hence it is clear that the invention is very much correct and the turbulence is avoided to a greater extent. As far as the system is concerned it is the simplest system and lower power consuming and more efficient and effective. Assembly and integration is very simple It is a well-established fact that for flow measurement, the fluid should be free from turbulence. But in the existing test setup, because of the presence of the conical throttle valve, the flow takes contraction in the entry itself and where and at which point, the flow will become laminar cannot be predicted exactly, and thereby additional turbulence generation is very likely. Hence it is desirable that it is to be eliminated in the test setup. The invention of the "flow straightener - throttle" of different matrices has been introduced in the new test setup to ensure the "hydrodynamic entry region" in the upstream. In the invented test set up, the fluid (air) is sucked through the "flow straightener -throttle" at the entry point itself by the fan in the upstream side. The air when enters in the flow straightener is at laminar state ensuring the hydrodynamic entry region. This air then passes through the orifice, down stream and then to the reducer. The air enters in the fan in the axial direction and leaves radial or axial. The measurements are carried out at various points across the airway in the turbulence free condition. This is ensured by the "flow straightener - throttle". To control the flow at varying speed, different configurations of "flow straightener - throttle" are used. The area ratio is obtained up to 100% by different matrices of "flow straightener - throttle" and hence the flow pattern improvement and which in turn improved the flow rate and lesser power consumption. The flow rate is increased to about 20% by the use of this invention. The subject application is a mere statement of invention, where many alternations and modifications are possible without deviating from the scope of the invention. The subject disclosure is for illustrative purposes only, hence the same should not be construed to restrict the scope of the invention. WE CLAIM: 1. A flow straightener - throttle for a fan testing rig comprising a plate (12) with at least one hole (13) having an air tight connection with an array of tubes (11) having at least one tube at one end which in turn is having an air tight connection with the corresponding identical holes in another plate at other end, for throtding and straightening the flow of the fluid, and producing the hydrodynamic entry region for laminar flow of a fluid or air in a duct (1). 2. A flow straightener - throttle as claimed in claim 1 wherein the said plate (12) is of circular or any other shape with plurality of holes. 3. A flow straightener - throttle as claimed in claim 1 wherein the said plates (12) and the said array of tubes (11) are having different matrices of holes of identical or different diameters (16) to obtain area ratio up to 100% 4. A flow straightener - throttle as claimed in claim 3 wherein said plates (12) have one central hole in air tight connection with one tube to obtain an area ratio up to 100% 5. A flow straightener - throttle as claimed in claim 3 wherein the holes (13) in plate (12) are selectively blocked to vary area ratio.

Documents:

3376-DEL-2005-Abstract-(24-10-2011).pdf

3376-del-2005-abstract.pdf

3376-DEL-2005-Claims-(24-10-2011).pdf

3376-del-2005-claims.pdf

3376-DEL-2005-Correspondence Others-(24-10-2011).pdf

3376-del-2005-correspondence-others.pdf

3376-del-2005-description (complete).pdf

3376-del-2005-description (provisional).pdf

3376-del-2005-drawings.pdf

3376-DEL-2005-Form-1-(24-10-2011).pdf

3376-del-2005-form-1.pdf

3376-del-2005-form-2.pdf

3376-del-2005-form-26.pdf

3376-del-2005-form-3.pdf

3376-del-2005-form-5.pdf

3376-DEL-2005-GPA-(24-10-2011).pdf