Homework 6

1. Derive Bernoulli’s equation for fluid flow from fundamentals. Give two following examples of this equation. i) A system with a pump which is not 100% efficient but maintaining NPSH criteria. This system is not ideal, so friction exists. ii) A system where all kind of valves, bends exist and the change of direction of flow may occur.

A please, B if you can

Which of the following statement about pump performance curves is incorrect? O Pump head curve indicates how much energy (or power) that a pump can provide to the flow at different discharges. O Break horse power (BHP) curve indicates the energy (or power) that a pump consumes at different discharges. O Best efficiency point (BEP) is the maximum efficiency that a pump may achieve within its operating discharge range. O Net positive suction head (NPSH) curve indicates the minimum NPSH values at different discharges in order to avoid cavitation.

Cavitation is an undesirable phenomenon that occurs in pumping systems. About cavitation incentrifugal pumps, analyze the following statements:I. The cavitation in centrifugal pumps depends only on the flow rate of the flowing fluid.II. The required NPSH must always be higher than available in order to avoid cavitation.III. The available NPSH (d) is related to the suction head and suction head losses. This onemust be greater than the required NPSH(r) (or NPSH(a)), which is related to the equipment.IV. The larger the suction pipe, the less chance of cavitation occurring.It is correct what is stated in:ALTERNATIVESa) I, just.b) III, only.c) III and IV only.d) I, II and III only.e) I, II and IV only.

What is the number of pumps needed in a series to meet the process requirements of a chemical plant, considering a flow rate of 3000 L/min of oil with a specific gravity of 0.85, a pressure of 120 kPa, a total pipe length of 900 m, a height difference of 25 m between the inlet and outlet, a pipe diameter of 0.2 m, and assuming each pump has an efficiency of 80% and can produce a head of 40 m? f = 0,02

Hydrodynamics pumps (WRITE LEGIBLY) 3. A centrifugal pump, operating at a speed of 1750 rpm and brake input power of 20 HP, delivers water at the rate of 600 gpm against a head of 104 ft. The impeller diameter is 10 in. If the impeller diameter is reduced to 9.5 in while maintaining the speed of 1750 rpm, determine the new (a) flow rate, in gpm; (b) head, ft; and (c) power, HP.  a. flow rate Answer : ____________________ gpmb. head Answer : ____________________ ftc. power Answer : ____________________ HP

For each statement, choose whether the statement is true or false, and discuss your answer briefly:                                                                               (a) If the rpm of a pump is doubled, all else staying the same, the capacity of the pump goes up by a factor of about 2.                                                   (b) If the rpm of a pump is doubled, all else staying the same, the net head of the pump goes up by a factor of about 2.                                               (c) If the rpm of a pump is doubled, all else staying the same, the required shaft power goes up by a factor of about 4.                                                (d) If the rpm of a turbine is doubled, all else staying the same, the output shaft power of the turbine goes up by a factor of about 8.

1. If the pump rotated at 2000 rpm and instead and used a 9" impeller, what would the head be when moving 400 gallons per minute? 2. How much input power would be required to move 200 gpm of gasoline in the pump described in the chart with an impeller diameter of 8 3/4"?

1. The figure shows a pump that draws 840 L/min of crude oil (s= 0.85) in an underground storage drum to the first stage of a processing system; a) If the total energy loss in the system is 4.2 N m/N of oil flow, determine the power transmitted by the pump to the fluid. b) If the energy loss in the steel suction line is 1.4 N m/N of oil flow, determine the pressure at the pump inlet

1.1 Define centrifugal pumps and briefly discuss their operating mechanisms. 1.2 Write the reasons for throttling a pump. What do we do if we do not use throttling? 1.3 Discuss the occurrence of surges in water supply systems and state the potential mitigation mechanisms in big cities. Also explain how pressure surges affects water quality in water supply systems. 1.4 Suppose the selected centrifugal pump for our use is not available in the market. Discuss how you select another pump available in the market and how we can utilize that pump. 1.5 Derive an equation for the available NPSH for a pump is bellow the water in the suction reservoir. Support your derivation by drawing.

Differentiate between Centrifugal and Reciprocating Pumps in detail by examples and their applications

The main of purpose of pumps is to transfer fluid from one point to another. If that's the only purpose, why so many designs?

Explain Reciprocating pump? List the components of a reciprocating pump and briefly describe each one's role.

n=1200 RPM nm = 0,95, " = nv= 0,95, n = 0,84, C2m = 3m/s, t₂ D₂ D₁ 2, Z = 8 157 mm, p₂ = 30°, B₂ = 27 mm,

In the system, 900 L/min of oil is pumped with (s=0.92), from an underground storage tank to the first stage of a processing system. If the loss in the suction line is 1.5m and the loss in the discharge line is 4.5m. The suction line is 2.5” and the discharge line is 1.5”. Determine a) the outlet pressure in psi of the pump. b) The power in hp of the pump

Part C Also, a turbine can be used before the pipeline exit to produce electricity. If the used turbine converts only two-thirds of the energy that the fluid will lose after passing through the turbine, what is the efficiency of this turbine? - Identify the most common water turbines and the limitations that exist within these different types? Although hydraulic turbines considered one of the most efficient power plants, their ecological impact is a big concern. Discuss this issue and suggest remedies for such problems by writing a short paragraph?

3) Please help me answer this mech. engineering question.

2/3 Summarize the rotor theory of centrifugal pumps, focusing on the following topics: Action of the rotor blades on the liquid Velocity equation

2. A centrifugal pump installation draws water from an underground well whose free surface is 50 m below ground level. Water is pump to a reservoir 6 m above ground. Suction pipe diameter is 150 mm and the discharge pipe diameter is 100 mm. The required capacity of the pump is 250 liter/sec. If the pump efficiency is 82%, determine the required brake power for the motor drive. a. brake power Answer : _______________ kW

What is the operation and components of an aircraft engine driven hydraulic pump?

4. "Pump A" usually operates at 1800 rpm using a 6 inch impeller, and its performance is described by the equation h, = 22-0.21 Q?. A homologous pump (i.e., "Pump B") from the same manufacturer operates at 1600 rpm with an 8 inch impeller. What is the performance curve for "Pump B"?

a. What are the characteristics of positive displacement pumps? b. What are the different types of positive displacement pumps? c. Differentiate positive displacement pump and centrifugal pumps?

For the single pump-pipe system below, what will be the changes for the operating point if we increase the pipe size but decrease the shaft speed of the pump? EB H₂ O The operating point will remain the same. O The operating point will occur either at a higher discharge or at a lower discharge, depending on the specific influence of each change. O The operating point will occur at a higher discharge. O The operating point will occur at a lower discharge.

A single pump and system have characteristics as shown on the graph below. Based on this information, estimate: (a) The flow rate with one pump online. (b) The flow rate if the pump's speed is doubled (c) The flow rate of two identical pumps operating in parallel (original pump speeds) (d) The flow rate of two identical pumps operating in series (original pump speed) (e) The flow rate if the system's static head doubles (f) Pump head (original system) if a valve is opened until the flow rate is 5.5 cfs 350 300 250 200 150 100 50 2 4 6. 8 10 12 Flow Rate (cfs) ·hp(req) •hp(avai) Head (ft)

2. Draw a neat sketch of Reciprocating Pumps and explain it working principle

What are centrifugal pumps' standard pump input power (kW) and water power (kW)?