B.TECH - Semester 4 thermal engineering Question Paper 2021 (dec)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Assume suilable values wherever necessary PART - A Answer all quesilons. Each question carries 4 marks. 1 Write short nales on the following: (a) Critical point
- Assume suilable values wherever necessary PART - A Answer all quesilons. Each question carries 4 marks. 1 Write short nales on the following: (b) Triple point
- Whal should be the desired properties of a working fluid in a Rankine cycle?
- What is meanl by reheal factor? Discuss ils relevance with T-S and h-s diagram.
- Explain Adiabalic llame temperature.
- Whal are the merits and demerits of a pre-combustion chamber?
- How is regeneralor useful in gas lurbine? 7 Compare knocking in SI engine and Cl engine. a Explain with itse helo of a neal sketch, working of a roots blower.
- Discuss the merts and demerils of rolary compressors over reciprocaling compressors. Answer three questions selecting one from each Module.
- (a) Describe with neat skelch working of La Moni Boiler.
- (b) In a modified Rankine cycle sleam is supplied at a pressure of 12 bas and temperature $200^{\circ} \mathrm{C}$. It expands adiabatically to 2 bar when it is released at constant volume to the exhatist pressure of 1 bar Delermine.
- (i) the work done per keg of sleam (ii) Modified Rankine eiliciency.
- (a) Explain warious methods of governing of steam turbines, giving merils and demprils of each method.
- (b) In a simple impulse sleam lurbine slage steam enters the nozzle al 15 bar, dry salurated with velocily of $150 \mathrm{~m} / \mathrm{s}$ Nozzle angle is $20^{\circ}$ and sleam leaves nozzle al 8 bas and enters into smooth blades considering nozzl...
- (i) the blade angles (ii) Une blading efficiency (iii) the slage elliciency
- (a) Discuss the effects of various engine variables on ignition lag.
- (b) Methane $\left(\mathrm{CH}_{4}\right)$ is burned with almospheric air. The Orsal analysis of line products of combustion is as follows: $$ \mathrm{CO}_{2}: 12 \%, \mathrm{O}_{2}: 2,4 \%, \mathrm{CO}: 0.5 \%, N_{2}: 85.1 \% $$ Determine the actu...
- (a) Show that for a simple ideal gas turbine cycle, the condition for maximum specific cotput in $T_{2}=T_{\Delta}$ when $T_{2}$ is the temperalute of air after isentropic compression in compressed and $T_{c}$ is the lemperature of the exhaust gases ...
- (b) An open cycle gas turbine plant has a single slage compressor and a single slage lurbine incorporaling a heal exchanger. The air suction temperature is $17^{\circ} \mathrm{C}$ and the pressure 1 bar. For an overall pressure ralio of 4.5 and shall...
- (a) Prove that the volumetric elliciency of a single-slage compressor is given by $I_{\text {hol }}=1+C-C\left(\frac{\rho_{2}}{\rho_{1}}\right)^{\text {lin }}$ where $C=\frac{V_{c}}{V_{s}}$
- (b) An axial flow compressor having len slages and with $50 \%$ reaction design compresses air is the pressure ralio of $5: 1$. The air enlers the compressor at $25^{\circ} \mathrm{C}$ and flows through it with a constant speed of $100 \mathrm{~m} / ...
- (a) Describe with a neat skelch the warking of a centrilugal compressor. How pressure changes lake place in impeller and diffuser?
- (b) In a test of a single-cylinder, single-acling reciprocaling air compressor having 100 mm bore and 125 mm stroke, air is laken from aumosphere al 1.013 bar and delivered through a value, which maintains a delivery pressure of $800 \mathrm{kN} / \m...