Types of Forces in Fluid Flow, Inertial Force, Viscous, Gravity, Pressure, Surface Tension, Elastic

In fluid flow problems forces acting on the fluid may be a single one and may not be. May be forces are acting combined. Force affects each particle (almost in case of small flow) and each particle affects the force via transfer of affect from one particle to other, from one layer to another adjacent layer. Fluid Particles resist the forces as per their stamina (Newton’s Third Law of Motion…. Action-Reaction). If Force is more powerful then affect will be shown bare eyes and is the intensity of acted force is very small the flow will be maintained itself.

Here the forces that participate in moving fluid are defined briefly. Each of this force has its affected effect in fluid flow problems. All forces can be defined easily with its name such as Inertial Force includes word inertia means related to Newton’s First law, similarly Gravity Force consists gravity means related to Newton’s Second Law etc…  Hence it is very simple to define any Force with its name basically. Moreover we are providing you here a “TTT” (Tip and Trick of Today) to learn these forces in series. To learn Forces in series is not necessary but yes it is in case of Determination of Dimensionless Numbers (Reynolds, Froude, Mach etc…). TTT is given below in the post that will help you.

Also Read: Basic Definitions in Fluid Mechanics, Properties of Fluid

Inertial Force: As we discussed above the name “Inertial Force” signifies itself linked with Inertia. As Newton’s Second Law of Motion derived the equation

Force = mass x acceleration

Simply this is the way to learn it. Thus Newton’s second law gives the definition of Inertial Force. And normally we say that F = ma, so it is the simplest method to learn it by force definition due to inertia. Inertial Force is indicated by F_i.

(Inertia is the property of anything that helps them to be in a state whether it is in stationary or in motion)

Viscous Force: It implies the viscosity, means the force acted due to viscosity is called “Viscous Force”. And if you remember viscosity exists due to shear stresses in the different layers of flowing fluid. You know the formula for Shear Stress.

i.e. Shear Stress (τ) = Shear Force/Area [or simply τ = F / A, therefore F = τA

Here the Shear Force is Viscous Force, so the formula will

Viscous Force (F_v) = Shear Stress x Area

Thus Viscous Force is the product of these two parameters one of them is the Area upon which the force is acting and another one is the produced shear stress. The symbol used to indicate Viscous Force is

(Viscosity is the basic property of any fluid to flow in different folds means layers, all liquids generally have this property.)

Gravity Force: This force acts due to gravity and due to gravity force acting is

F = mg

(in case of gravity gravitational acceleration is considered instead of acceleration), so this force is “Gravity Force”. It is denoted by F_G.

So make definition for it. Product of mass and gravitational acceleration is “Gravity Force”.

Pressure Force: Think that we are gonna give the definition for pressure. So Pressure intensity will be the product of force and reciprocal of area. Simply the force is Pressure Force and it will be the product of Pressure Intensity and Cross-Sectional Area.  It denotes F_P

Surface Tension Force: For surface tension force we should learn the definition of Tension. It is denoted by F_{ST .}

We know that

T = F / L

Surface tension and the length of surface products this force which acts in flowing fluid.

Elastic Force: Elasticity of any material is defined by Stress, so basically by stress formula. It is denoted by

F_{E .}

Thus product of elastic stress and Area is defined as “Elastic Force”.

Importance of these Forces: Dimensional Analysis is considered with the help of these forces. All the dimensionless parameters are calculated with help of these forces.

Easy and Best Way to learn definition of forces: Just the formulas keep in mind and make definitions your own…

TTT: Suppose that you have seen your result and want to know about your friend then you will ask in Hindi + English “Aai Vi Grand Percentage See ?” { “ vkbZ oh Grand Percentage See ? ” }

This is the Trick of Today learn the above bold words and understand those words as you are using them in your college time to ask your friend using these words.

| When you write this thinking you will write “I V G P S E” |

Here I stands for Inertial, V stands for Viscous, G stands for Gravity, P stands for Pressure, S stands for Surface tension and E stands for Elastic Forces.

Basic Definitions in Fluid Mechanics, Properties of Fluid explain with examples…..

Some Basic Definitions in Fluid Mechanics, Properties of Fluid explain with examples…..

Density: Density indicates the compactness of molecules of fluid means how compact they are arranged. If the space between any two adjacent molecules is in range of very small quantity, the fluid will be much denser. Density is a factor that affects the weight, Flow property, Volume, Mass, Molecular Compaction and many other relative quantities of Fluid. Density basically specifies How much harder our fluid is?  Simply Mass per unit volume is Density but to learn formula is not the way to understand Density, the fact what the funda is should also clear. Unit of density is Kg/m3. A Greek symbol Rho “ρ” is used to denote it.

Example: Let us assume we take a cube of edge 1m of any material [volume of this box is 1 cubic meter]. We filled it with water. Now the amount of mass in that cube as per unit volume is defined as Density of Fluid. Density of fluid is 1000Kg/m3, means in a cube of edge 1m can contain 1000Kg water.

Density is also called as “Mass Density”.

Density = Mass of Fluid/ Volume of Fluid

The word Denser even came from the term density. The mass of water in a closed box is greater than the mass of gas in the same box, that is why it is clear that the molecules of water has much cohesive property than the molecules of gas. Hence in the same volume water has a large quantity of molecules therefore weight and mass of that structure will be large. This all phenomenon indicates that water is much denser than gas. Similarly in case of Water and Mercury, Mercury (Hg) occurs little space to cover its molecules and in that same box Mercury covered a large quantity hence it is denser than water.

Specific Weight: Also named as “Weight Density”. We were talking about the mass in the above topic; here the mass term is replaced with Weight. Thus the term Weight occurred in unit volume is “Specific Weight” of the Fluid. Mathematically Specific Weight will be equals to weight of the fluid if the container has one cubic meter volume. Specific weight not includes the amount of matter present in the fluid but it includes the force (w) exerted by the molecules towards the earth under the gravitational acceleration (g).

Example: A same cubic container of side 1m is taken. As measurement occurs in the density case same things are done in this case except measurements are done taking Weight instead of Mass (m) of Fluid. Simply specific weight signifies the weight of fluid contained in a unit volume. It specifies the stiffness a well as the compactness of fluid particles.

Specific Weight = Weight of Fluid (W) / Volume of Fluid (V)

          Sp. Weight = m x g / V ………………….................................... [W = m x g]

          Sp. Weight = Density x g = ρg

Specific Volume: This property of fluid says that How much volume will be obtained in 1Kg mass?  It is basically the reciprocal of density. Hence its unit is m3/Kg. simply the definition for Sp. Volume is “Volume occupied in a unit mass is called as Sp. Volume.”

        Sp. Volume = Volume of Fluid / Mass of Fluid

        Sp. Volume = 1 / ρ

Specific Gravity: This property of fluid is defined in terms of Sp. Weight or weight density. How much percentage of weight density our liquid has with respect to the standard fluid (taken as water)? A fluid weight density to standard fluid weight density ratio is termed as Sp. Gravity.

         Sp. Gravity = wt. density of Fluid / wt. density of standard Fluid

In mostly liquid cases standard fluid is taken as Water (which has pH value of 7) because it is easily available in economy and the all type of measurements can easily operate upon it. Operations and reactions are conveniently resulted to the aim in case of water means each type of reaction shows its result upon it. Air is taken as standard fluid if we are taking measurements about Gas.

                             S = wt. density of Fluid / wt. density of Water

As the nominator and denominator both have same dimensions so Sp. Gravity is a dimensionless quantity.

Viscosity of Fluid: Viscosity is another property of fluid (say quality of fluid) which shows its “Quality to Flow in Layers”. The density and pressure of fluid is not same in all the layers of fluid flow while it changes from upward to downward incrementally. The liquid becomes denser as dip high. Hence the refractive index changes undergo due to change in denseness of fluid from one layer to another. Upper layer weighted upon the adjacent below layer and by the collision Shear Stresses produced. The below layer is denser than above so the velocity of above layer or water surface is higher. The adjacent below layer is respectively stationary and resists the flow of above layer. This stress produced is Shear stress in fluids flow.

Viscosity of fluid is denoted by Mu “μ” and its unit for measurement is N-s/m2.

What is an Arc? Types of arc, How an Arc can be drawn in AutoCAD? Methods

What is an Arc? Types of arc, How an Arc can be drawn in AutoCAD? Uses and methods to draw an arc...

Arc (Definition):

An Arc is the attachment or joining of two points with no straightness means not in displaced direction but via curvic turns. Arc is basically a part of a Circle or an Ellipse. All arcs are drawn basically in Anti-Clockwise Direction.

Types of Arc: There are two types of Arc possible for designing in AutoCAD. These are-

Circular Arc: These are the arcs that are made up by Circle. Circular arc means the arc that is a part of a circle. If we extend circularly in both directions a circle will form. To draw a circular arc firstly draw the circle by C enter and then draw a line that sectioned the circle into two equal or unequal parts (one part has the part of circle of your requirement this is circular arc). Now apply explosion and trim out the extra unwanted part. Now erase that line using E enter. The arc prepared now is a circular Arc. This method of drawing arc is basically an example that we can do a thing with many ways.

Elliptical Arc: These are the arcs that are made up by Ellipse. If we extend the elliptical arc ends circularly in both the directions it is not necessary that a circle will form instead a parabolic structure will shown. If we cut even a little part from the ellipse the remaining and the cutting both would be arcs of elliptical type. Eleven methods are used to draw an elliptical arc as defined below.

Methods to draw an Arc:

1.    3-Point Arc: As the name indicates that three points are making an arc, same it requires first point or start point, then second point and finally the end point. This arc goes through all the three points. If any one or more parameters are not known then other methods are used to draw the arc. 3-Point arc is basically a very simple type of arc and the requirement is of just three points. To draw a 3Point arc type ARC and press enter. Specify Start Point, Second Point and then End Point. This type of arc is used whenever only some positions are known instead of other radial and dimensional parameters.

2.    Start, Centre, Angle Arc: This type of arc is made by start point, centre point and the angle between two ends from the centre point. This method is used when a single point is known with the centre point of the arc. And also the angle between start point and end point is known then this method is helpful. Here angle is the degrees deformation occurred from the line connecting centre to one point to the another one that connects centre point to the

3.    Start, Centre, End Arc

4.    Start, Centre, Length Arc

5.    Start, End, Angle Arc

6.    Start, End, Direction Arc

7.    Start, End, Radius Arc

8.    Centre, Start, End Arc

9.    Centre, Start, Angle Arc 

10. Centre, Start, Length Arc

11.Continuous Arc 

What is a point? Types and styles of points, use and working of points in AutoCAD 2014

 What is a point? Types and styles of points, use and working of points in AutoCAD...., full detailed description about a point..., Use of DDPTYPE command

A point (Definition):-

A point may be defined as a beginning or ending of any element. It is also called “node”, even node is a point where two or more lines or segments are connecting to each other. Two points make a line and more than two points make a polygon joining together. Co-ordinate system cannot be considered without a point, because a point is the starting for any segment. 

Types of point:-

These types of points are available for drafting. These are defined as below:

First Point: It is defined as a starting of any structure design. Firstly the point which is appointed to start the segment is called as “First Point”. For example we want to draw a line then we’ve to first appoint a reference point from which the segment or element will be drawn. This point is First Point.

Second Point: From which the segment go through the point is termed as “Second Point”. It is not required if not known against other parameters. It makes the drawing easy. For instance an arc is to be drawn in a drawing then firstly first point should be appointed then second point should pointed out if possible otherwise arc can be drawn by the other known parameters. From the second point if a curve is to be drawn curvic corners will be drawn and make the shape of curve very smoothly. If we discuss about the making process for a circle, a two point circle is required for the second point.

Next Point: it is the point coming after and after the previous point. For example we are making a drawing consists of a great number of lines joining lines continuously means that the ending point of first line is connected to the starting point, then we will not take line or also can say we will not enter the command for drawing the line again and again. So we take a line once and draw our design without coming out from the command and we will draw a continuous line and we will specify other and all other points. These other points are called as “Next Points”.

Center Point: Center point is defined as a point used basically for the circle related components. If the center point of a circle is attached to any circumference point, radius of circle is obtained. So the point from which the circle is made having some radius is termed as “Center Point” of that circle. An arc has also a center point and for it the center point is the center of the circle from which the arc is prepared.

End Point: For the drawing of a line second point may be called as the end point if the line is drawn by only two points. End point is basically the point where a segment is stopped to go. If a closed loop is made the first point would be the end point provided that the loop is made by line segment or arc etc... Actually end point is the last or final point where our structural element ends. While drawing an arc by First End Radius method, First End Direction method or First End Angle method is the clear example for the end point because it required first point then end point and when end point of the arc is appointed direction or angle or radius of the circle through which the arc is cut out is to be specified.

Mid Point:  Mid point is the point that intersects any line segment into two equal parts. The line segment may be of linear and also a curve or an arc. If Object Snap is ON (Mid Point must be checked ON) in AutoCAD midpoint of the segment is shown automatically. Mid Point of the line or of an arc has it’s differ symbol than first point, end point and center point to indicate itself. 

Tangent Point: It is the point that indicates the tangent to any point on the circle. Tangent on a point means the line that make an angle of 90 degrees to the line that connects that point to the center of the circle.

Perpendicular Point: The point that shows the 90 degrees angle between two lines as called as Perpendicular Point. It is not necessary that the point should be in the center of line, but the point may be anywhere upon the line and the other line must make 90 degrees angle.

Nearest Point: It is the point that indicates the nearest stage to draw the next point for an appointment. For instance two lines are cutting a line vertically and we have to draw a line from a different point to the point between the intersectional points of those two lines then the next point on the lying line will show the nearest path to draw.

Styles or designs of a point: Many different types of symbols are used to indicate the points. For example the point may be look like a hollow circle, a fill circle, a circle having two cross sectional lines or may be a simple point. The style for end point looks like a rectangle while center point has a circle type style whereas midpoint indicates itself by a triangle like symbol. The indication of Tangent point looks like a line is over the circle and nearest point shows its design as two triangles joined with one vertices over one another. An intersection shows design like X means intersection of two lines. Perpendicular point looks like a vertical line is standing over the midpoint of a horizontal line. Some other symbols are-

  

How to change Point style in AutoCAD?

Type DDPTYPE in the command bar and press enter, the above type of Point Style Dialog Box will open, now select your desired point style and go on your work.

You can also change point style using menu options. Go to Format Menu then click on fourteenth option Point Style the same dialog box will open. This option will change the styles of all the points have been pointed on the maximize viewport (black screen).

Use of Points:

Points are used as reference for any structure. It is also used as for indications to draw the other objects. For Signification of any position anywhere points are used.

What is a Line? Kind, Types and working, command for a Line, Polyline, construction line, Xline, Ray, Spline, Contour and Multiline....

What is a Line? Kind, Types and working of line in AutoCAD...Use of Line Command... What is the command for a Line, Polyline, construction line, Xline, Ray, Spline, Contour and Multiline?

A Line (Definition):

A line may be called as the connection of two points directly in displacement direction. A line consists of minimum two points and maximum any number. If other points are in displacement direction then it will be called as a single line made by multiple number of points while the points are not in displacement direction and angle is changing somewhere then it would be called as combination of lines. A connection between two points linearly is called as a line segment. 

Kind of Lines:-

Straight Line: A straight line is the connection between two points with no angle deformation. A line between a single first point to the end point is called a Straight Line. Only two points are not indispensable for making a straight line but more than two points between first and end point can make a line straight if they are the roots of that particular line. If we draw four lines each perpendicular to other then a Rectangle formation will be formed. To draw a straight line the commands for using is L and then press enter. The difference between a rectangle and the rectangle made by line is that rectangle shape is a single object while four different lines are used to make a rectangle and these are editable separately. 

Continuous line: A line starting from the end point of previously drawn last line is called as Continuous Line. As continuous word indicates its continuity, so a continuous line will not stop to be until the press of “Esc” button or say that until we come out from the command. Continuous line draws the combination of lines with stops in its path. If we click on any element in the drawn structure that particular line segment will select and if we want to change in any line or any part of this continuous line, it is possible. No command is for it and this is not a type of line but a quality of line in AutoCAD. If you are come out from line command and want to continue the drawn line press L again and come in line command and specify the first point of the line be the end point of last drawn line. Then the line will continue from there and hence this quality of line is called as a property of Continuity of a line. Therefore line is a continuous line in AutoCAD.

PolylineIt is a line that draws the combination of different straight lines element in a single object formation and if we click on any element of this structure the entire Polyline object will select. And if we want to change the format of any single element then it is not possible until the explosion. Polyline is used to draw a single poly object directly means to an object combination of straight lines and arcs etc... To draw Polyline type in command window box PL and press enter or use Space Button. Specify the first and other next points and if you wanna start an arc press A enter and its first point would be the end point of recently drawn line segment and other parameters are used to draw now the desired output.

Construction Line:It is also called as X line and use for reference to draft any other structure. Construction line doesn’t have any starting point nor have any end point. To draw X line press XL and enter. X line requires only a single point anywhere on the Drawing Canvas. And when this point is appointed the direction, horizontal, vertical, angle or offsets are selected out as per requirement. The length of construction line is not measurable and having co-ordinates from negative infinity to positive infinity. As a graph shows the light color lines same in AutoCAD Construction Lines are used.

Ray Line: This line is almost similar to construction lines but the difference is that construction line has no starting and no ending point while Ray lines has starting point but no ending point. These Ray lines are also used as reference line and most usable in the drafting where many lines are to be drawn from a single point. As Sun rays come from Sun similarly taking Sun as origin point and rays as ray lines structures are drawn. To draw Ray line press RAY in Command window and enter. Same, in Ray lines a point of origin is appointed first and then the required direction is draft out. The extra part out of the structure can be trimmed out by using Trim Command i.e. TR and then double enter.

Multiline: Multiline is an assembly of multiple parallel lines, such as two parallel lines are going to make the design of a road. To draw multiline press ML and then press enter. It will ask the first point and the other next points where the path is to be drawn. Multiline is also a single object that can be explosive. MLSTYLE is used to change the number and other styles of Multiline. It firstly asks about the first point of the multiline. But the confusion that now if we have four parallel line segments in multiline then on that point which one line would start from it. So justification is used for it. Press J enter for change it after coming in the multiline command. Justification asks you about the Top, Zero and Bottom. For going into the command type the first character for entering in it like enter T for Top, etc... Here top means that the top line in multiple parallel lines would be upon the specified first point. Similarly for zero and bottom the Zero line and the bottom line of the multiline would be upon the specified first point and the element will start from it to design the structure.

Spline: Spline means spherical line or curvic line. A line that connects different points with rounded or sinusoidal corners is called Spline. To draw Spline type SPL and press enter. A spline object is a single object and it will be selected entirely if click on anywhere on the drawn element. So Spline is used to draw a curvic line. A sinusoidal wave can be drawn by Spline. Curves on Roads, Spillways etc...can be shown by Spline. Type otherwise CON and press enter. This command is to make a Contour. Contour is also called as a Spline. So by it to draw a contour over some high or little elevation for showing Spline is also useful.