2014-10-03

engineering basic-3

What is specific speed of the turbine?

It is defined as the speed of a turbine which will develop unit power under unit head.

What are the unit quantities?
Unit quantities are the quantities which are obtained when the head on the turbine are unity.

Explain about characteristic curves
of a hydraulic turbine
Characteristic curves of a hydraulic turbine are the curves with the help of which the exact behavior and performance of the turbine under different working conditions can be known.

What do you mean by pipe flow?
            1. Pipe flow has no free surface and subjected to hydraulic pressure only.
            2. The cross section of the flow is fixed


List the instrument used to measure open channel flow
            1. pitot tube
            2. Ultrasonic flow instrument.
            3. Dropper instrument
            4. Gurley instrument.

What are the types of flow profile?
  •             Mild slope profile
  •             Steep slope profile
  •             Critical slope profile
  •             Horizontal bed profile
  •             Adverse slope profile


What do you mean by coefficient of velocity?

V1=Cv (2gH)

Where,
 V1 = velocity of jet
Cv  = coefficient of velocity
H = head of the turbine.

What are the main parts of pelton wheel turbine?
1.         Nozzle and flow regulating arrangement
2.         Runner with buckets
3.         Casing
4.         Breaking jet

What are the main mechanisms of Radial flow reaction turbine?
            1. Casing
            2. Guide mechanism
            3. Runner
            4. Draft tube

What is the term most economical section?
A section of the channel is said to be most economical when the cost of construction of the channel is minimum. But the cost of construction mainly depend up on the excavation and lining to keep the cost minimum ,the wetted perimeter for a given discharge should be minimum.

What are the conditions of rectangular channel of best section?
The two conditions are breadth is equal to two times the depth (b=2d) and hydraulic mean depth is equal to half the depth (m=d/2)

What do you mean by open channel flow?
            1. Open channel flow has a free surface which is subjected to atmospheric pressure.
            2. In open channel flow the cross section is irregular.

What is multistage pump?
If centrifugal pump consists of two or more impellers the pump is called multistage pump. To produce a high head impellers are connected in series .To produce high discharge impellers are connected in parallel.

What is Manometric head?
Manometric head is the head against which a centrifugal pump has to work.
                        Hm = Hs +hd +Hfs +Hfd + (vd2/2g)

Where, Hm – manometric head
            Hs - suction head
            Hd – delivery head
            Hfs – friction head loss in suction pipe
            Hfd – friction head loss in delivery pipe

What is slip of a reciprocating pump and negative slip?
Slip is defined as the difference between theoretical discharge and actual discharge.
 If actual discharge is greater than theoretical discharge negative value is found this negative value is called negative slip.

What do you know coefficient of discharge?
It is defined as the ratio of actual discharge by theoretical discharge. It is denoted By Cd.

What do you know Drop down curve?
The water surface has a convex profile upwards this curve is called drop down curve.


What are the classifications of hydraulic turbine according to the type of energy at inlet ?
(a)        Impulse turbine and
(b)        Reaction turbine

What are the types of turbine according to direction of flow through runner?
(a)        Tangential flow turbine
(b)        Radial flow turbine
(c)        Axial flow turbine
(d)       Mixed flow turbine

What are the types of turbine according to the head at the inlet of the turbine?
(a)        high head turbine
(b)        medium head turbine
(c)        low head turbine

The more fouling fluid should be on which side of a shell & tube heat exchanger?

            Tube side (because it is easier to clean)

What are the types of turbine according to the specific speed of the turbine?
(a)        Low specific speed turbine
(b)        Medium specific speed turbine
(c)        High specific speed turbine.

What are the classifications of flow in channels?
            1. Steady flow and un steady flow.
            2. Uniform flow and non uniform flow.
            3. Laminar flow and turbulent flow and
            4. Sub critical, critical and super critical flow.

What are the types of Non uniform flow?
(i)         Rapidly Varied Flow (R.V.F)
(ii)        Gradually Varied Flow (G.V.F)

What do you know about laminar and turbulent flow?
     Laminar flow:
     The flow in open channel is said to be laminar if the Reynolds number ( Re) is less than  500.

     Turbulent flow:
     If the Reynolds number is greater than 2000 it is called turbulent flow.

List energy conservation opportunities in a steam distribution and utilization system.
1)         Fix steam leaks and condensate leaks
2)         Ensure process temperatures are correctly controlled.
3)         Maintain lowest acceptable process steam pressures
4)         Remove or blank off all redundant steam piping
5)         Ensure condensate is returned or re-used in the process.
6)         Recover boiler blow down.
7)         Check operation of steam traps.
8)         Remove air from indirect steam using equipment
9)         Reduce the work done by steam
10)       Insulate pipelines

What do you mean by specific energy curve?
It is defined as the curve which shows the variation of specific energy with respect to depth of flow.

 Write down the use of centrifugal pump?
            1. Used in deep sump and basement
            2. The high discharge capacity
            3. It is driven by electric motors

Define open channel flow?
The term open channel flow denotes the gravity-driven flow of a liquid with a free surface.

What do you mean by stream lining?
Streamlining is adding a faired tail section to reduce the extent of separated flow on the downstream portion of an object.

What do you know about Hub or Boss?
It is the core part of the axial flow turbine where the vanes are attached.

Under what head the propeller turbine take water? 
About 100 m head the propeller turbine take water. When the vanes are fixed to the hub and they are not adjustable the turbine is called propeller turbine.

What are the uses of Kaplan turbine?
            1. To produce more output.

            2. The efficiency of the turbine is more.