fosTEMFACULTY OF ENGINEERING AND TECHNOLOGY

NAME : LIM WEI CHUNID : I14004874PROGRAMME : BMEGILECTURRER : Dr CHUA KENG HOOSUBJECT : FLUIDS DYNAMIC IntroductionThe aim of this project is to examine the ideal cross-section area configuration of the fluid flow when two different ball spans are being used. The areas that effects the flow rate in our situation categorized into minor losses in pipes where it is known as the losses caused by bending, fitting, and valve. The main problem due to the valve are expansion and contraction, where it is witnessed to be the subject of research my many great minds. Numerous hypothetical and trial examinations have been accounted for writing on the above issue. In spite of the fact that endeavors have been made to depict the base pressure as capacity of different parameters of the procedure nevertheless it seems to be the issue that none have given a concrete theory to be a fundament of our research whereas all the assumptions only confine the use of the outcome.To use the Flo EFD software stimulation we are able to find the flow rate of the valve, with the graph, and can be easily alter the ball valve size.

TheoryA ball valve enable shut-off and/or purposes of control. They have a round closure

element that contains a matching pair of rounded seats. These seats allow

necessary sealing to take place. Theball valve pressure rating and materials used

determines what kind of seat is required.

At whatever point the uniform cross-area of a pipeline is hindered by the consideration of a channel fitting, for example, a valve, twist, intersection or stream estimation gadget, then a weight misfortune will be acquired. The estimations of these misfortunes, which are at times misleadingly alluded to as minor losses, must be incorporated in a pipeline's aggregate resistance if lapses in pump and framework coordinating or stream figuring's for a given weight differential are to be avoided.

In this treatment, the term 'separation loss' has been decided to characterize weight misfortunes crosswise over such fittings, as it is felt that this term depicts well the physical phenomena which happen at such hindrances in the pipeline. By and large, the stream differentiates from the funnel dividers as it goes through the deterring channel fitting, bringing about the era of whirlpools in the stream, with ensuing pressure loss, as demonstrated in Figure 1 for the instance of a sudden enlargement. This is like a channel releasing into a tank yet this time it doesn't slam into static liquid however with slower moving liquid in the vast funnel. The pressure loss coefficient is given by the accompanying statement.

Figure 1 : Sudden EnlargementFurthermore, the head loss assigned of "major" and "minor" don't essentially mirror the relative significance of every sort of loss. For a channel framework that contains numerous segments and a moderately short length of funnel, the minor loss might really be bigger than the major loss where at some situations of the large pipe system the major losses are neglected due to their relatively small effect on the pressure loss.Procedure1. Run FloEFD. Click File > Open. In the Open dialog box, browse to the Ball Valve.SLDASM assembly located in the A1 - Ball Valve folder and click Open (or double-click the assembly). By following the instructions in Blackboard a project was created with the specification below;Set the flow rate at 0.0 + the last three digit of your student ID (cubic meter per second). For an example, 3-digit ID = 513, Q=0.0513 m^3/s. (Note: if the number is less than 0.01, add 0.05, for an example, 3-digit ID = 007, Q=0.0507 m^3/s)2. Methane oil was used3. Specified boundary conditions are as below ;Specify the engineering goal Run the calculationAnalyse the design variant in the ball fillet radiusCompare result and data

Results

Normal filletLiquid: olive oilFlow rate: 0.00874 m/s

Figure 2: Methane ileration on normal fillet

Figure 3: pressure Figure 4: velocity along along the XY length of the tube the XY length of the tube

When with 1.5 fillet analysis

Figure 5 Methane ileration on 1.5 fillet

Figure 6: pressure figure 7: velocity alongAlong the XY length of the tube the XY length of the tube

DiscussionThe primary motive of our project is to fully understand the methods to design a valve and to calculate the losses. With accordance to our objective the variation that we have performed is alter the radius of the ball valve and measure the flow rate of the effect. The losses are usually written in the form hL = KL(V22/2g), where K is the coefficient of resistance.Lets firstly discuss the losses that were witnessed occurred when the alteration of diameter.

Sudden expansion is the loss due to increase in diameter of the pipe flow. Due sudden expansion of the pipe section, flow is decelerated abruptly resulting in the formation of eddies due to the separation of flow from the boundary and thereby, causing the loss of energy.

Figure 8 : Sudden Expansion

The loss of energy can be determine by using the impulse momentum equation in addition to the Bernoulli's and continuity equations and is given by the following expression hexp = [(V1 - V2 )2]/2g

The equation is then a required expression and is known as the Borda's Carnot equation which can be also expressed as hexp = (V12/2g)[1-(V2/V1)]2= (V12/2g)[1-(A1/A2)]2(By using the continuity equation; A1V1=A2V2)

hexp = Kexp(V12/2g)where Kexp is the loss coefficient of the expansion, which is equal to [1-(A1/A2)]2Exit loss is when A2 reaches infinity, and then the head loss faces a sudden enlargement and is expressed as V12/2g. Since the liquid speeds are captured in the extensive supply, the whole dynamic vitality of the funnel is dispersed into intermolecular vitality bringing about the misfortune coefficient to be 1. Therefore, the exit loss only equals to the velocity head.

Sudden contraction is noted to be one of the losses where it is caused by the decrease in diameter as shown below.

Figure 9 : Sudden Contraction

Loss of energy due to sudden contraction is expressed byHcon = V22/2g [(1/CC) - 1]2 = Kcon(V22/2g)Where Kcon is the loss coefficient of the contraction which is equal to [(1/CC) - 1]2, here Cc is the coefficient of contraction. Although area A1 is not explicitly involved in the equation, the value of Kcon is dependent on d1/d2. It is also noted that the energy loss for the sudden contraction is much lesser then the energy loss for sudden enlargement. Entry loss is when it is noted that A1 reaches infinity, where the value of K is 0.5. This constraining circumstance compares to the stream from a huge supply into a sharp edged funnel, if the end of the channel does not jut into the reservoir. The head loss is then denoted by 0.5(V22/2g) and is known as the entry loss.

Erosion losses are an unpredictable capacity of the framework geometry, the liquid properties and the stream rate in the framework. By perception, the head loss is generally relative to the square of the stream rate in most engineering streams. This is expressed in the Darcy-Weisbach equation for head loss due to friction; hf = f (L V2 / 2g).

Let L = length of the pipe between sections 1 and 2. d = diameter of the pipe f = factor of frictionhf = head loss due to friction. p1 = pressure at section 1 v1 = velocity at section 1 p2, v2 = the corresponding values at section 2.

Applying Bernoullis equations for real fluid at sections 1 and 2, we get

But z1=z2, and V1=V2, as the funnel is level and the breadth of the channel is same in both areas.

Darcy friction factor is defined as,

Giving us Darcy's equation of, hf = f (L V2 / 2g).

ConclusionAs a summary, it is seen that there are many factors that will affect the flow rate. The main factors were identified and could be categorized as two major factors of loss. They are known as the major and minor factors, where the main consideration is the frictional resistance between the liquid particles and the limit mass of the funnel itself and the minor components are because of the change of speed either in size or course or both. These changes make eddie by the streaming liquid. To overcome water driven resistance, certain measure of vitality controlled by the streaming liquid gets scattered as warmth vitality and therefore there is loss of vitality toward stream.

The pressure drop increments with higher delta speed and henceforth with higher mass stream rate. This point is the most helpless point for funnel harm. We found that the weight drop for the typical filet is more prominent than the 1.5 filet. As an ensuing, higher speed is attain to in the ordinary filet. Along these lines, the typical filet range has a superior for utilization.

Reference

Available at:https://books.google.com.my/books?id=0clZbfwgiyUC&printsec=frontcover&dq=A+Textbook+of+Fluid+Mechanics+and+Hydraulic+Machines+in+SI+Units,&hl=en&sa=X&ei=rWc1VeD2JZLn8AW22oHACg&ved=0CCAQ6AEwAQ#v=onepage&q=A%20Textbook%20of%20Fluid%20Mechanics%20and%20Hydraulic%20Machines%20in%20SI%20Units%2C&f=false(Accessed: 10th April 2015).

Dr. R. K. Bansal (2015)A Textbook of Fluid Mechanics and Hydraulic Machines,Available at:https://books.google.com.my/books?id=0clZbfwgiyUC&printsec=frontcover&dq=A+Textbook+of+Fluid+Mechanics+and+Hydraulic+Machines+in+SI+Units,&hl=en&sa=X&ei=rWc1VeD2JZLn8AW22oHACg&ved=0CCAQ6AEwAQ#v=onepage&q=A%20Textbook%20of%20Fluid%20Mechanics%20and%20Hydraulic%20Machines%20in%20SI%20Units%2C&f=false(Accessed: 10th April 2015).Ball valve - Wikipedia, the free encyclopedia. 2015.Ball valve - Wikipedia, the free encyclopedia. [ONLINE] Available at:http://en.wikipedia.org/wiki/Ball_valve. [Accessed 30 april 2015].