Mechanical engineering interview question and answer:-
What is cooling tower? Give the Schematic Diagram of cooling tower. What is the difference between cooling towers and condensers?
Answer: Cooling Tower Classification with schematic diagram
What are different types of condensation processes?
Answer: There are mainly two types of condensation processes
Film-wise condensation and
Draw the diagram of combined cycle power plant. (Combination of Brayton Cycle and Rankin Cycle). Show topping and bottoming cycle in the diagram.
Answer: Please follow the link : Combined Cycle Power Plant with Topping and Bottoming Cycles
What are major and minor head losses in a fluid flow system?
Answer: Major loss is known as the losses that occur in the pipes. Minor losses are head losses which occurs due to bends and elbows (additional parts in the straight pipe system).
What is valve? What is the function of butterfly valve?
Answer: Valves are devices which can control the flow of fluid. By controlling means directing and regulating the flow.
In a butter fly valve there is a disc which is hinged to the body. And there is an operator. When operator moves the butterfly valves disc also rotates and creates or blocks passage for the fluid to flow. When the disc is parallel to the flow the liquid passes and when the disc is completelyperpendicular the flow also completely stops. Please watch this video for a complete understanding of the butterfly valve.
Which type of compressor is used in gas turbine?
Answer: In Gas Turbine cycle three types of compressors are used
These are Axial compressor, centrifugal compressor and mixed flow compressor. Axial compressors are very popular for gas turbine power plants because these are compact and need less space for medium to large thrust gas turbines.
What happens in superheating process?
Answer: In superheating the temperature is increased of the fluid with increasing its pressure.
Name some of the flow meters.
Answer: Orifice meters, Venturi meters, Rotameters , nozzles
What is a nozzle? What happens in a nozzle?
Answer: nozzle is a device which can control the direction of the fluid along with changing some of its properties. Nozzle is especially used for increasing the velocity of the fluid stream. Generally nozzle is a tapered tube. It is used where high velocity and low pressure is required. It depends on the continuity equation. According to continuity equation if the flow rate is to be remained same the product of area and velocity should remain same on the inlet and outlet. So if area decreases then the velocity increases.
What is the expression of a polytropic process?
Answer: Polytrpoic is a thermodynamic process . It follows the relation .
polytropic process expression
What is the percentage U238 in nature?
Relation of absolute pressure, gage pressure and atmospheric pressure.
Answer: Absolute pressure = Atmospheric Pressure + Gage Pressure
Which one has greater efficiency for the same compression ratio? Diesel engine or petrol engine? Explain.
Answer: For same compression ratio petrol engine has greater efficiency then diesel engine. Otto cycle or petrol engine cycle rejects lesser heat for the same compression ratio than the diesel engine cycle. That’s why it has better efficiency for same compression ratio.