Title of Invention	"APPARATUS AND METHOD OF FLOW VISUALIZATION USING WET PAINT TECHNIQUE"
Abstract	Many an engineering problem associated with fluid flow need an understanding of the interaction of the flow with the solid boundary. Visualization of the flow-boundary interaction is the first step towards understanding of the phenomenon. Techniques available to visualize the flow on the bed instantaneously include hydrogen bubble technique and injection of a color dye like potassium permanganate solution etc. However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obtain a long duration flow pattern around a body mounted on the bed, one needs a methodology that gives the (low pattern resulting from long duration flow interaction on the bed. Flow visualization using wet paint is one such technique, which achieves the objective of obtaining a flow pattern of long duration flow-structure interaction. It provides a method to study the pattern of stresses and the resulting scour extent around hydraulic structures. It is an easy and economical tool to record the streakline pattern at the flow boundary in the presence of a hydraulic structure.

Title of Invention

"APPARATUS AND METHOD OF FLOW VISUALIZATION USING WET PAINT TECHNIQUE"

Abstract

Many an engineering problem associated with fluid flow need an understanding of the interaction of the flow with the solid boundary. Visualization of the flow-boundary interaction is the first step towards understanding of the phenomenon. Techniques available to visualize the flow on the bed instantaneously include hydrogen bubble technique and injection of a color dye like potassium permanganate solution etc. However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obtain a long duration flow pattern around a body mounted on the bed, one needs a methodology that gives the (low pattern resulting from long duration flow interaction on the bed. Flow visualization using wet paint is one such technique, which achieves the objective of obtaining a flow pattern of long duration flow-structure interaction. It provides a method to study the pattern of stresses and the resulting scour extent around hydraulic structures. It is an easy and economical tool to record the streakline pattern at the flow boundary in the presence of a hydraulic structure.

Full Text	Title of invention: APPARATUS AND METHOD OF FLOW VISUALIZATION USING WET PAINT TECHNIQUE Field of Invention: This invention relates to the novel method of visualization of the shear stress pattern, scour mechanism and the scouring horseshoe vortex around a bridge pier or a model hydraulic structure on a rigid bed. Background of invention Rivers are natural flowing systems, which cannot be controlled by manmade structures. Construction of a bridge pier across a river obstructs the flow. The flowing water in the river scours the sediment around the bridge piers. Thus, all bridges and structures associated with waterways are potentially at risk of failure due to hydraulic scour. It has been esiimated that 60% of all river bridge failures is attributable to undermining of pier foundations following scouring or erosion of the channel bed. During 1961 to 1976, out of 86 major bridge failures, 46 failed as a result of excessive scour near piers (Murillo 1987) Breusers et al. (1977) present a state of the art report on the mechanism and prediction of scour depth around a bridge pier. The bridge failures of Ganga Pul at Makamah (River Ganga) and on river Tapi are examples of major bridge failures due to scour in India. Reports of Ministry of Railways, India (1967, 1968, and 1972) describe the history of work carried out in India in the direction of bridge pier scour. The major cause of scouring leading to exposing of the pier is a system of vortices. It commences with the formation of adverse pressure gradient at the upstream front of pier, which results in the formation of this vortex. This vortex wraps around the pier in the form of a horse shoe and dislodges sediment from the bed and releases it downstream. Many an engineering problem associated with fluid flow need an understanding of the interaction of the flow with the solid boundary. Visualization of the flow-boundary interaction is the first step towards understanding of the phenomenon. Techniques available to visuallize the flow on the bed instantaneously include hydrogen bubble technique and injection of a color dye like potassium permanganate solution etc. However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obtain a long duration flow pattern around a body mounted on the bed, However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obiain a long duration flow pattern around a body mounted on the bed, one needs a methodology that gives the flow pattern resulting from long duration flow interaction on the bed. Wet paint technique is one such technique, which achieves the objective of obtaining a flow pattern of long duration flow-structure interaction. Object of invention: To provide a method to study the pattern of stresses and the resulting scour magnitude and extent around hydraulic structures. To provide an easy and economical tool to record the streakline pattern at the flow boundary in the presence of a hydraulic structure. Statement of invention: A method to study the interaction of flow with the solid boundary and to obtain a flow pattern ol long duration at the flow-structure interaction junction. A summary of invention: Method o! visualization using wet paint technique comprising steps of preparation of a false bed of using a thin plate on which the model, around which the physics of the flow is to be studied, is fixed. The width of the plate should preferably be equal to the width of the flume. It should be sufficiently long so that the upstream and downstream flow patterns should not be disturbed. The upstream front edge of the plate is chambered on one side so that the fluid flows over the plate with minimum disturbance A brief description of the accompanying drawing: In drawings which illustrate specific embodiments of the invention Figure ! shows a plan view of final wet paint impressions of flow around a circular cylinder mounted on a flat plate. Figure 2 show, the formation of streaklines and the separation zone around the cylindrical pier model Figure 3 shows the formation of streaklines through wet paint imprints for flow around an abutment on a rigid bed. Figure 4 shows the development of flow pattern in the form of low speed streak lines (streamlines lor steady flow). Figure 5 (a) shows the perspective view of a pier on a caisson model on a rigid bed. Figure 5 (b) shows the plan view of final paint imprints for a pier on a caisson model on a rigid bed Figure 6 (a) shows the perspective view of a pier with a delta wing like passive device model on a rigid bed Figure 6 (b) shows the plan view of final paint imprints for a pier with a delta wing like passive device model on a rigid bed. Detailed description of the invention with reference to drawing /examples: The wet paint technique essentially involves preparation of a false bed or using a thin plate on which the model, around which the physics of the flow is to be studied, is fixed as shown in Figure 1. The width of the plate should preferably be equal to the width of the Hume. It should be sufficiently long so that the upstream and downstream flow patterns should not be disturbed. The upstream front edge of the plate is chamfered on one side so that the fluid flows over the plate with minimum disturbance Among the first applications of the techniques was a model bridge pier mounted on an aluminium plate, henceforth termed as the base plate. To begin with, the base plate was thoroughly cleaned and a thin coat of a base paint, preferably white, was given. This was allowed to dry. Thereafter, oil paint (usually yellow) of appropriate consistency, prepared by mixing a little quantity of thinner to commercially available paint, was spread by a paint brush or hand sprayer. Care was always taken to ensure that the consistency of paint was such that it would start to flow gradually towards the lower side if the plate was tilted in any direction. Without wasting any more time, the plate was made 10 rest on the floor of the flume in which the flow had already been maintained to set specifications of velocity and depth. The paint started to move under the effect of shear stresses on the bed and left behind a consequential pattern in accordance with the shear stresses. Development of flow pattern takes place in the form of low speed streak lines (streamlines for steady flow) as shown in Figure 4. The plate had to be in this state for fairly long duration of the order of 2-3 hours till the paint thinned down to a stage of no further movement. The duration for development of flow imprints on the plate and the model depends upon the consistency (or viscosity) of the paint and flow intensity. If the paint is highly viscous, flow pattern may not be distinct while on the other hand if the paint is less viscous, the flow pattern develops quickly but may get washed away. After taking the plate out from the running flume it was dried with a warm air blower to help evaporate excess water drops. The plate in dry state, with distinct flow imprints on the bed as shown in Figure 5, could be used for analysis. Figure 6 shows the perspective view and the plan view of final paint imprints for a pier with a delta wing like passive device model on a rigid bed. The streak lines could be photographed, photocopied or traced to keep a permanent reference of the imprints. We Claim: 1. Apparatus for determining the scoured area in front of an obstruction (i.e. bridge pier, abutment, spur, dyke, pipeline) comprising of the model obstruction rigidly fixed to the non-corrosive metal plate forming the rigid bed to act as pier and having a chamfered leading edge provided on the upstream side of flow and commercially available oil paint of required consistency provided on plate for studying the streaklines and actual flow pattern of water on the bed.. 2. The apparatus as claimed in Claim 1 wherein the plate is made of aluminium 3. The apparatus as claimed in Claim 1 wherein the obstruction is rigidly fixed to the aluminium plate. 4. The apparatus as claimed in Claim 1 wherein upstream front edge (leading edge) of the plate is chamfered at 45 degree. 5. Method of flow visualization using wet paint technique for determining the scoured area in front of a bridge pier (or abutment, spur, dyke, pipe, on the pier) comprising of the steps of chamfering the leading edge of the plate, fixing the model bridge pier on base plate, applying a thin coat of base paint and allowing it to dry, spraying an oil paint of appropriate consistency over the plate and placing the plate in already established flow to visualize the form and shape of low speed streaklines and a flow pattern on the bed. 6. The method as claimed in Claim 1 wherein oil paint used is of yellow pigment. 7. The method as claimed in Claim 1 wherein duration for development of flow imprints on the plate and the model depends upon the consistency (or viscosity) of the paint and flow intensity. Consistency of the paint is such that it is neither fully washed away nor refusing to move under the action of pre-set flow conditions. 8. The method of flow visualization using wet paint technique is described in the specifications and illustrated in drawings.

Full Text

Title of invention:
APPARATUS AND METHOD OF FLOW VISUALIZATION USING
WET PAINT TECHNIQUE
Field of Invention:
This invention relates to the novel method of visualization of the shear stress pattern, scour mechanism and the scouring horseshoe vortex around a bridge pier or a model hydraulic structure on a rigid bed.
Background of invention
Rivers are natural flowing systems, which cannot be controlled by manmade structures. Construction of a bridge pier across a river obstructs the flow. The flowing water in the river scours the sediment around the bridge piers. Thus, all bridges and structures associated with waterways are potentially at risk of failure due to hydraulic scour.
It has been esiimated that 60% of all river bridge failures is attributable to undermining of pier foundations following scouring or erosion of the channel bed. During 1961 to 1976, out of 86 major bridge failures, 46 failed as a result of excessive scour near piers (Murillo 1987) Breusers et al. (1977) present a state of the art report on the mechanism and prediction of scour depth around a bridge pier. The bridge failures of Ganga Pul at Makamah (River Ganga) and on river Tapi are examples of major bridge failures due to scour in India. Reports of Ministry of Railways, India (1967, 1968, and 1972) describe the history of work carried out in India in the direction of bridge pier scour.
The major cause of scouring leading to exposing of the pier is a system of vortices. It commences with the formation of adverse pressure gradient at the upstream front of pier, which results in the formation of this vortex. This vortex wraps around the pier in the form of a horse shoe and dislodges sediment from the bed and releases it downstream. Many an engineering problem associated with fluid flow need an understanding of the interaction of the flow with the solid boundary. Visualization of the flow-boundary interaction is the first step towards understanding of the phenomenon. Techniques available to visuallize the flow on the bed instantaneously include hydrogen bubble technique and injection of a color dye like potassium permanganate solution etc. However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obtain a long duration flow pattern around a body mounted on the bed,
However, these aids need an instantaneous photograph to observe and preserve the flow pattern. In order to obiain a long duration flow pattern around a body mounted on the bed, one needs a methodology that gives the flow pattern resulting from long duration flow interaction on the bed. Wet paint technique is one such technique, which achieves the objective of obtaining a flow pattern of long duration flow-structure interaction.
Object of invention:
To provide a method to study the pattern of stresses and the resulting scour magnitude and extent around hydraulic structures. To provide an easy and economical tool to record the streakline pattern at the flow boundary in the presence of a hydraulic structure.
Statement of invention:
A method to study the interaction of flow with the solid boundary and to obtain a flow pattern ol long duration at the flow-structure interaction junction.
A summary of invention:
Method o! visualization using wet paint technique comprising steps of preparation of a false bed of using a thin plate on which the model, around which the physics of the flow is to be studied, is fixed. The width of the plate should preferably be equal to the width of the flume. It should be sufficiently long so that the upstream and downstream flow patterns should not be disturbed. The upstream front edge of the plate is chambered on one side so that the fluid flows over the plate with minimum disturbance
A brief description of the accompanying drawing:
In drawings which illustrate specific embodiments of the invention
Figure ! shows a plan view of final wet paint impressions of flow around a circular
cylinder mounted on a flat plate.
Figure 2 show, the formation of streaklines and the separation zone around the
cylindrical pier model
Figure 3 shows the formation of streaklines through wet paint imprints for flow
around an abutment on a rigid bed.
Figure 4 shows the development of flow pattern in the form of low speed streak lines
(streamlines lor steady flow).
Figure 5 (a) shows the perspective view of a pier on a caisson model on a rigid bed.
Figure 5 (b) shows the plan view of final paint imprints for a pier on a caisson model
on a rigid bed
Figure 6 (a) shows the perspective view of a pier with a delta wing like passive device
model on a rigid bed
Figure 6 (b) shows the plan view of final paint imprints for a pier with a delta wing
like passive device model on a rigid bed.
Detailed description of the invention with reference to drawing /examples:
The wet paint technique essentially involves preparation of a false bed or using a thin plate on which the model, around which the physics of the flow is to be studied, is fixed as shown in Figure 1. The width of the plate should preferably be equal to the width of the Hume. It should be sufficiently long so that the upstream and downstream flow patterns should not be disturbed. The upstream front edge of the plate is chamfered on one side so that the fluid flows over the plate with minimum disturbance
Among the first applications of the techniques was a model bridge pier mounted on an aluminium plate, henceforth termed as the base plate. To begin with, the base plate was thoroughly cleaned and a thin coat of a base paint, preferably white, was given. This was allowed to dry. Thereafter, oil paint (usually yellow) of appropriate consistency, prepared by mixing a little quantity of thinner to commercially available paint, was spread by a paint brush or hand sprayer. Care was always taken to ensure that the consistency of paint was such that it would start to flow gradually towards the lower side if the plate was tilted in any direction. Without wasting any more time, the plate was made 10 rest on the floor of the flume in which the flow had already been maintained to set specifications of velocity and depth. The paint started to move under the effect of shear stresses on the bed and left behind a consequential pattern in
accordance with the shear stresses. Development of flow pattern takes place in the form of low speed streak lines (streamlines for steady flow) as shown in Figure 4. The plate had to be in this state for fairly long duration of the order of 2-3 hours till the paint thinned down to a stage of no further movement. The duration for development of flow imprints on the plate and the model depends upon the consistency (or viscosity) of the paint and flow intensity. If the paint is highly viscous, flow pattern may not be distinct while on the other hand if the paint is less viscous, the flow pattern develops quickly but may get washed away.
After taking the plate out from the running flume it was dried with a warm air blower to help evaporate excess water drops. The plate in dry state, with distinct flow imprints on the bed as shown in Figure 5, could be used for analysis. Figure 6 shows the perspective view and the plan view of final paint imprints for a pier with a delta wing like passive device model on a rigid bed. The streak lines could be photographed, photocopied or traced to keep a permanent reference of the imprints.

We Claim:
1. Apparatus for determining the scoured area in front of an obstruction (i.e. bridge
pier, abutment, spur, dyke, pipeline) comprising of the model obstruction rigidly fixed to the non-corrosive metal plate forming the rigid bed to act as pier and having a chamfered leading edge provided on the upstream side of flow and commercially available oil paint of required consistency provided on plate for studying the streaklines and actual flow pattern of water on the bed..
2. The apparatus as claimed in Claim 1 wherein the plate is made of aluminium
3. The apparatus as claimed in Claim 1 wherein the obstruction is rigidly fixed to the
aluminium plate.
4. The apparatus as claimed in Claim 1 wherein upstream front edge (leading edge) of
the plate is chamfered at 45 degree.
5. Method of flow visualization using wet paint technique for determining the scoured
area in front of a bridge pier (or abutment, spur, dyke, pipe, on the pier) comprising
of the steps of chamfering the leading edge of the plate, fixing the model bridge pier
on base plate, applying a thin coat of base paint and allowing it to dry, spraying an
oil paint of appropriate consistency over the plate and placing the plate in already
established flow to visualize the form and shape of low speed streaklines and a flow
pattern on the bed.
6. The method as claimed in Claim 1 wherein oil paint used is of yellow pigment.
7. The method as claimed in Claim 1 wherein duration for development of flow
imprints on the plate and the model depends upon the consistency (or viscosity) of
the paint and flow intensity. Consistency of the paint is such that it is neither fully
washed away nor refusing to move under the action of pre-set flow conditions.
8. The method of flow visualization using wet paint technique is described in the
specifications and illustrated in drawings.

Documents:

1377-del-2005-abstract.pdf

1377-del-2005-claims.pdf

1377-del-2005-correspondence-others.pdf

1377-del-2005-correspondence-po.pdf

1377-del-2005-description (complete).pdf

1377-del-2005-drawings.pdf

1377-del-2005-form-1.pdf

1377-del-2005-form-13.pdf

1377-del-2005-form-18.pdf

1377-del-2005-form-2.pdf

1377-del-2005-form-3.pdf

1377-del-2005-form-5.pdf

1377-del-2005-form-9.pdf

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Patent Number

199934

Indian Patent Application Number

1377/DEL/2005

PG Journal Number

31/2009

Publication Date

31-Jul-2009

Grant Date

06-Oct-2006

Date of Filing

30-May-2005

Name of Patentee

BALDEV SETIA

Applicant Address

ASST. PROF.IN CIVIL ENGINEERING, NATIONAL INSTITUTE OF TECHNOLOGY KURUKSHETRA-136119(HARYANA), INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	BALDEV SETIA	ASST. PROF.IN CIVIL ENGINEERING, NATIONAL INSTITUTE OF TECHNOLOGY KURUKSHETRA-136119(HARYANA)
2	THIMMAIAH GANGADHARAIAH	FORMER PROFESSOR IN CIVIL ENGINEERING I.I.T. KANPUR-208016(U.P) PRESENTLY EMERITUS PROF.AT SIT TUMKUR-572103(KARNATAKA)

PCT International Classification Number

E02B 3/12

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA