THER08004 2019 Thermodynamics

Be familiar with thermal resistance, contact resistance, the critical radius of insulation and be able to solve practical conduction problems involving multiple materials.

Be familiar with and be able to solve basic problems in free convection using knowledge of buoyancy, velocity and thermal boundary layers, relevant Dimensionless numbers, and governing equations and correlations.

Be familiar with and be able to solve basic problems in forced convection, using knowledge of laminar and turbulent flows, entrance region and fully developed flow, flow across flat plates, cylinders in cross flow, tube arrays.

Demonstrate knowledge of heat exchangers, their types, overall heat transfer coefficient, log mean temperature difference, and calculation of efficiency/effectiveness.

Demonstrate an understanding of and solve problems relating to refrigeration and heat pump cycles.

Understand the regeneration process and be able to solve problems when applied to gas and vapour power cycles such as Rankine cycle, Brayton cycle.

The course will be delivered primarily by lecture where key concepts will be explained and followed through with graded exercises leading on to practical problem examples. Repetitive (property and steam tables, interpolations) exercises will be supplemented on Moodle outside of class to ensure student fluency and proficiency. A mini-assignment or project comprising an industrial design brief for a heat exchange or thermal management device will form a self-learning component of the module.

This subject will be assessed by a midterm project and end of term assessment. Minor exercises and assignments will also form part of the assessment.

Repeat assessment will be by way of sitting another examination on the subject. Alternatively, at the discretion of the lecturer, assignments covering the deficient areas of the course may be set.

• Conduction: practical conduction and insulation issues, thermal resistance, the composite wall, contact resistance, radial conduction, critical radius of insulation.

• Fundamentals of natural convection: density and buoyancy, Grashof Number, Prandtl No. velocity, laminar and turbulent flows, thermal boundary layers, governing equations and related correlations, Reynolds analogy.

• Fundamentals of forced convection: Velocity and thermal boundary layers, governing equations and related correlations, Nusselt No., internal and external flows, Laminar, turbulent and separated flows; flat plates, cylinders in cross flow, tube arrays, jet impingement, entrance region and fully developed flow, flow in pipes and ducts.

• Regeneration and Reheat in Gas and Vapour power cycles including Brayton, Stirling and Rankine. Afterburners in jet engines. Effects on efficiency, cost benefit considerations.

• Heat Exchanger Performance and Design: Heat exchanger types, overall heat transfer coefficient, log mean temperature difference, effectiveness, fouling, methodology for design.

• Refrigeration Cycles, Refrigerators and heat pumps, Reversed Carnot Cycle, Ideal and actual vapour Compression cycles, efficiency, COP, refrigerant properties.

 Indicative Practicals

1 Tutorials as required