Thermodynamics and Heat Transfer Flashcards
6 cards from real ME or MEng Master of Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Thermodynamics and Heat Transfer flashcards as text
Which thermodynamic cycle is the theoretical standard for spark-ignition gasoline engines?
Answer: Otto cycle
The Otto cycle models the idealized operation of a spark-ignition internal combustion engine with constant-volume heat addition.
What does the Clausius inequality state about a thermodynamic cycle?
Answer: The cyclic integral of dQ/T is less than or equal to zero
The Clausius inequality states that the cyclic integral of δQ/T ≤ 0, with equality for reversible processes, forming the basis of the second law.
In a heat exchanger, the LMTD method stands for:
Answer: Logarithmic Mean Temperature Difference
LMTD (Logarithmic Mean Temperature Difference) is used to determine the driving force for heat transfer in a heat exchanger.
The thermal efficiency of a Carnot heat engine operating between 600 K (hot) and 300 K (cold) is:
Answer: 50%
Carnot efficiency = 1 − T_cold/T_hot = 1 − 300/600 = 0.50 or 50%.
Fourier's Law of heat conduction relates heat flux to:
Answer: The negative of the temperature gradient
Fourier's Law states q = −k∇T, meaning heat flux is proportional to the negative temperature gradient.
Which dimensionless number is used in convective heat transfer to relate inertial forces to viscous forces in a fluid?
Answer: Reynolds number
The Reynolds number (Re = ρVL/μ) compares inertial to viscous forces and determines laminar vs. turbulent flow regimes.