Thermodynamic Exam Paper 2012- Level 1
SUBJECT AREA: MECHANICAL ENGINEERING
Module Code: Module Title:
Time allowed Hours:
Answer FOUR questions: TWO from Section A, TWO from Section B.
Examiner(s): Prof. T. Megaritis and Dr R. Kirby Special Stationery Requirements:
Thermodynamic and Transport Properties of Fluids, GFC Rogers and YR Mayhew. Only School approved calculators are allowed. Use a separate answer book for each section. If you submit answers to more questions than specified, final marks for the examination will be determined using the best marks which satisfy the rubric.
- 1 ___________________________________________________________________________ SECTION A A1. (a) Explain the meaning of the terms: One-Dimensional Fluid Flow, Steady Fluid Flow, and Incompressible Fluid Flow. [15%] Write the Continuity Equation for a steady, one-dimensional flow and define each term in the equation. If the flow is incompressible what is the simplified form of the equation? [20%] A vertical venturi meter carries a liquid of relative density (specific gravity) of 0.8 and has an inlet diameter of 150 mm and a throat diameter of 75 mm. The pressure tapping at the throat of the venturi is 150 mm above the pressure tapping at the inlet of the venturi. The volumetric flow rate through the venturi is 40 l/s. (i) Assuming that the coefficient of discharge of the venturi is 1.00 (neglecting frictional losses), calculate the pressure difference between the inlet and the throat of the venturi. [40%] A vertical U tube mercury manometer is connected to the pressure tappings at the inlet and the throat of the venturi. The tubes above the mercury are full of the liquid flowing through the venturi meter. Calculate the difference between the levels of the mercury in the two sides of the manometer. [25%]
DATA Gravitational acceleration g = 9.81 m/s2