Fundamentals of Thermal Engineering
- What are thermodynamics, mechanical engineering and industrial engineering? Explain with examples.
- What is thermodynamic system, surrounding and boundary? Explain types of system and boundary with suitable neat sketch.
- What are properties, state, process and cycle? Explain with the help of suitable diagrams.
- What are the different types of processes (total five) involved in the thermodynamics? Explain with the help of diagrams. Also derive the formula for workdone.
- Explain the zeroth law, first law and second law of thermodynamics with examples and neat sketch.
- What is entropy, energy and energy interaction?
- What are the reversible and irreversible processes? Explain with neat sketch.
Internal Combustion Engine (I.C. Engine)
- What is Heat engine? How these engines are classified (make a flow chart)?
- Explain the Internal combustion (I.C. Engine) and External combustion (E.C.) engine in detail (explain with applications)?
- Classify the Internal Combustion Engine on the basis of different factors.
- What are the components of I.C. engine? Explain with neat sketch.
- What are the terminologies involved in I.C. engine? Explain in detail.
- Explain the working of four-stroke petrol engine (Spark-Ignition) with neat sketch. Also derive the efficiency for the four stroke petrol (S.I.) engine with neat sketch. (also draw the P-v, T-s diagram)
- Explain the working of four-stroke Diesel engine (Compression Ignition) with neat sketch. Also derive the efficiency for the four stroke petrol (C.I.) engine with neat sketch. (also draw the P-v, T-s diagram)
- Explain the working of Two-stroke petrol engine (Spark-Ignition) and Two-stroke Diesel engine (Compression Ignition) with neat sketch. Also drive the efficiency formula for 2-stroke petrol and 2-stroke Diesel engine. (Efficiency will be derived same as that of 4-stroke petrol and 4-stroke diesel engine)
- Differentiate between 4-stroke and 2-stroke engine.
- Differentiate between spark ignition (petrol) and compression ignition (diesel) engine.
- Write the short notes on (with formulae):
Indicated power (IP) and Indicated Thermal efficiency
Brake power (or BHP) and Brake Thermal efficiency
Friction power (FP)
Calorific value (QV)
Mean effective pressure (Pm)
Specific fuel consumption (sfc)
Relative efficiency or Efficiency Ratio
- A four stroke, four cylinder diesel engine running at 2000 rpm develops 60 KW. Brake thermal efficiency is 30% and calorific value of fuel (CV) is 42 KJ. Engine has a bore of 120 mm and stroke of 100 mm. Take ra=1.15 Kg/m3, air-fuel ratio=15:1 and ηm=0.8. Calculate: (i) fuel consumption (kg/sec) (ii) Air consumption (m3/sec) (iii) volumetric efficiency, (iv) indicated thermal efficiency (v) brake mean effective pressure.
- An engine operates on air-standard otto cycle has compression ratio equal to 7. The condition at start of the compression are 0.1 MPa and 300 K. The pressure at end of the heat addition is 4 Mpa. Determine (i) Thermal efficiency (ii) Net work done per kg of air where Cv = 0.718 KJ/kg K.= 1.4, and (iii) mean effective pressure.
- In Otto cycle air at 17ºC and 1 bar is compressed adiabatically until the pressure is 15 bar. Heat is added at constant volume until the pressure rises to 40 bar. Calculate the air-standard efficiency, the compression ratio and the mean effective for the cycle. Assume Cv=0.717 KJ/KgK and R=8.314KJ/kmolK.
- In an engine working on diesel cycle inlet pressure and temperature are 1 bar and 17ºC respectively. Pressure at the end of adiabatic compression is 30 bar. The ratio of expansion i.e. after constant pressure heat addition is 5. Calculate the heat addition, heat rejection and the efficiency of the cycle. Assume γ=1.4, Cp=1.004KJ/Kg K and Cv=0.717 KJ/Kg K.
- What is the principle of the pump? How they are classified (through flow chart)? (Explain with applications)
- What is Reciprocating pump? Explain the single acting and double acting reciprocating pump with neat sketch.
- What is the principle of centrifugal pump? Explain the construction and working of centrifugal pump with neat sketch. (including three casing)
- Differentiate between reciprocating and centrifugal pump.
- In a flat belt drive, derive the expression for tension ratio which is T1/T2.
- What is Initial tension in belt? Explain the effect of centrifugal tension in the belt drive and also find condition for maximum power transmission.
- Derive expression of length of : (a) Open belt drive (b) Cross belt drive.
- Define slip and creep with respect to belt drive.
- What is belt drive? Describe briefly types of belt drive.
- Define: (a) Module (b) Pressure Angle (c) Pitch Point (d) Addendum (e) Dedendum (f) Flank (g)Circular Pitch (h) Pitch Circle
- Difference between Belt, Gear and Rope drive.
- Enumerate advantage and disadvantage of Belt, Gear and Rope Drive.
- The speed of a driving shaft is 80 rpm and the speed of the driven shaft is 120 rpm. The diameter of the driving pulley is given as 600 mm. Find the diameter of the driven pulley in the following case a) If the belt thickness is negligible b) If belt thickness is 5 mm c) If total slip is 10% (considering thickness of belt) d) If slip is 2% on each pulley (considering thickness of belt).
- A leather belt of density 1000 Kg/m3, thickness 10 mm is used to transmit a power of 10 KW From a pulley of diameter 1.2 and running at 250 rpm. Determine the width of the belt taking centrifugal tension into account. If the angle of lap is 160° and coefficient of friction between belt and pulley is 0.25. Assuming allowable stress for the leather belt is 1.5 MPa.
- An open belt drive transmits a power of 3 KW. The linear velocity of the belt is 3 m/sec. The angle of the lap on the smaller pulley is 160°.Coefficient of friction between belt and pulley is 0.25. Determine the effect on power transmission in the following cases:-Initial tension in the belt increase by 10 %.
Angle of lap increase by 10 %. Assume same speed and tension in the tight side.
Coefficient of friction increase by 10 % for the same initial tension.
- Two Spur gear having the velocity ratio 1/3, driven gear has 72 teeth of 8 module and rotate at 300 rpm, calculate number of teeth and speed of the driver gear also calculate the pitch line velocity.
- For the compound gear train shown in figure
What is the train velocity ratio?
Determine the angular velocity of output gear (gear 8) and its direction
Refrigeration & Air-Conditioning(RAC)
- Define a) COP b) Ton of refrigeration c) Refrigerant
- Explain with neat sketch the principle and construction of Vapor Compression Refrigeration System (VCRS) and Vapor Absorption Refrigeration System (VARS).
- What should be properties of common refrigerant?
- Explain working of Domestic Refrigeration System with neat sketch.
- Distinguish between heat engine, heat pump and refrigerator.
- Write a short note on Window air conditioner and Split air conditioner.
- Write 8 difference between Air Conditioner and Refrigerator.
- Define a) WBT b) DBT c) DPT d) Relative Humidity e) Humidity Ratio f) Degree of Saturation g) Specific Volume.
- Carnot refrigeration cycle absorb heat at 280 K and reject heat at 310 K.
(a) Calculate the COP of refrigeration cycle. (b) If the cycle absorb 1120 KJ/min of heat at 280 K how many KJ of work is required per second? (c) If Carnot heat pump operate between same temperatures limit find COP. (d) How many KJ/min of heat will the heat pump deliver at 310 K if it absorb 1120 KJ/min of heat at 280K.
- The capacity of the refrigerator is 200 TR when working between -4℃ and 22℃. Determine the mass of ice produced per day from water at 22℃. Also, find the power required to drive the unit. Assume that the cycle operate on reversed Carnot cycle and latent het of ice is 336 KJ/kg