Thermal Systems 3 (EML3703)

Course Description

Thermal Systems 3 covers fundamental equations related to fluid mechanics and heat transfer as well as design of thermal fluid systems.

Within the SCNS taxonomy, EML is the Mechanical Engineering prefix. The University of West Florida publishes this at 3 semester hours, prerequisite EML3016, giving approximately 45 contact hours at the standard university lecture ratio. It is the third and culminating course of the UWF thermal-fluids sequence — EML3015 (thermodynamics) → EML3016 (fluid mechanics) → EML3703 (heat transfer and thermal system design).

The word that distinguishes this course is design. The first two courses build analytical machinery; this one applies it to systems that must be specified, sized, and justified. Analysis asks what a given heat exchanger does; design asks how large it must be, which type to choose, and what the trade-off against pumping power and cost is — and that reframing is what makes this the course closest to professional thermal engineering.

Learning Outcomes

Required Outcomes

• Apply the differential formulation of conservation laws for mass, momentum, and energy.
• Describe the Navier-Stokes equations and identify the assumptions behind simplified forms.
• Analyze boundary layers and their thermal counterparts.
• Apply Fourier's law and analyze steady conduction in multiple geometries.
• Construct and solve thermal resistance networks.
• Analyze extended surfaces and calculate fin performance.
• Analyze transient conduction using lumped capacitance and one-dimensional methods.
• Apply numerical methods to conduction problems.
• Apply correlations for forced convection in internal and external flows.
• Apply correlations for free convection.
• Describe boiling and condensation heat transfer.
• Analyze radiation exchange between surfaces using view factors.
• Solve combined-mode heat transfer problems.
• Analyze heat exchangers using LMTD and effectiveness-NTU methods.
• Select a heat exchanger type appropriate to a duty.
• Size a heat exchanger for a specified duty.
• Account for fouling and its effect on performance over time.
• Analyze piping systems, calculate pressure drop, and size pumps.
• Match a pump to a system curve and identify the operating point.
• Describe cavitation and calculate net positive suction head.
• Evaluate the trade-off between heat transfer performance and pumping power.
• Perform a thermal system design incorporating economic considerations.
• Document a thermal system design with calculations and justification.

Optional Outcomes

• Describe computational fluid dynamics and its limitations.
• Describe thermal system optimization methods.
• Describe HVAC system design.
• Describe electronics cooling and thermal management.
• Describe renewable and solar thermal systems.
• Relate content to the FE examination specification.

Major Topics

Required Topics

• Differential conservation laws
• Navier-Stokes and simplifying assumptions
• Velocity and thermal boundary layers
• Steady conduction
• Thermal resistance networks
• Fins and extended surfaces
• Transient conduction
• Numerical conduction methods
• Forced convection correlations
• Free convection
• Boiling and condensation
• Radiation and view factors
• Combined-mode problems
• Heat exchanger analysis: LMTD and NTU
• Heat exchanger selection
• Heat exchanger sizing
• Fouling
• Piping systems and pressure drop
• Pump selection and system curves
• Cavitation and NPSH
• Heat transfer versus pumping power
• Thermal system design with economics
• Design documentation

Optional Topics

• Computational fluid dynamics
• Thermal system optimization
• HVAC design
• Electronics cooling
• Solar thermal systems
• FE examination alignment

Resources & Tools

• Fundamentals of Heat and Mass Transfer (Incropera, DeWitt, Bergman & Lavine) — the standard, and the book thermal engineers keep.
• Heat and Mass Transfer (Çengel & Ghajar) — more approachable, excellent figures.
• A Heat Transfer Textbook (Lienhard & Lienhard) — free and legally downloadable from MIT; genuinely excellent.
• Design of Thermal Systems (W. F. Stoecker) — the classic on the design and optimization side this course names.
• NCEES FE Reference Handbook — free; heat transfer and fluid sections are examined.
• CoolProp — free and open source property library.
• EES (Engineering Equation Solver) — widely licensed by institutions and very well suited to iterative thermal system design.
• Manufacturer selection software and catalogues — free: Grundfos and Xylem for pumps, Alfa Laval and API for heat exchangers. Real thermal design is done with these, and using one on a project is directly employable experience.
• ASHRAE Handbook — the operative reference for HVAC and building thermal design; institutions frequently provide access.
• Python with CoolProp, NumPy, and Matplotlib — free; building a parametric design tool is what practising engineers do.

Career Pathways

• Thermal systems engineer — SOC 17-2141; the direct destination.
• HVAC design engineer — a very large Florida employment sector; cooling load dominates design in this climate and the market is substantial.
• Power plant engineer — condensers, feedwater heaters, and cooling systems; FPL, Duke Energy Florida, TECO, JEA, and Siemens Energy in Orlando.
• Process engineer — heat exchanger networks in chemical and food processing.
• Electronics cooling engineer — a growing specialization as power densities rise; relevant to Florida's electronics and defence manufacturers.
• Aerospace thermal engineer — spacecraft thermal control; the Space Coast is a direct pathway.
• Energy efficiency engineer and commissioning agent.
• Refrigeration and cold chain engineer — Florida's agriculture and food distribution sector.
• Renewable energy engineer — solar thermal and heat recovery.
• Applications engineer for pump and heat exchanger manufacturers.
• Licensed professional engineer — the PE Mechanical HVAC and Refrigeration and Thermal and Fluid Systems depth exams are built substantially on this content.

Special Information

⚠ Design means trade-offs — and the central one is heat transfer against pumping power

• Better heat transfer almost always costs pressure drop. Turbulence promoters, smaller tubes, and higher velocities all improve the heat transfer coefficient and all increase the pumping power required — and that trade-off is the defining tension of thermal system design.
• Pumping power scales steeply with velocity, so a modest increase in flow to improve heat transfer can cost disproportionately in operating energy.
• Optimize over the life of the system, not the purchase price. A larger heat exchanger costs more initially and less to run, and the correct answer depends on energy cost and expected life.
• Fouling is a design allowance, not an afterthought. Real exchangers foul, performance degrades, and a design without fouling resistance is a design that fails to meet duty within a year — and in Florida's water and marine applications fouling is aggressive.
• Approach temperature drives area sharply. Chasing the last few degrees of approach requires disproportionate surface area, and knowing where that curve turns is design judgement.
• Select before you size. Shell-and-tube, plate, and air-cooled exchangers suit different duties, fluids, pressures, and maintenance regimes.
• Check the operating point, not just the duty. A pump and a system have separate curves and they meet at one point — a pump selected on rated flow rather than on the intersection will not deliver it.
• NPSH is not optional. Insufficient net positive suction head causes cavitation, which destroys impellers and is entirely predictable from the calculation.

⚠ Correlations are empirical — check their validity before you use them

• The convection coefficient is not a material property. It depends on geometry, flow regime, fluid properties, and temperature difference.
• Every correlation states a validity range — Reynolds number, Prandtl number, geometry, entrance effects — and using one outside its range produces a wrong answer with no warning.
• Evaluate properties at the temperature the correlation specifies — film, bulk, or surface — and getting this wrong shifts results noticeably.
• Expect tens of percent accuracy, not three significant figures. Reporting a convection result to five digits misrepresents what is known, and design margins exist because of it.
• Check the flow regime first. Laminar and turbulent correlations differ substantially, and the transition region is genuinely uncertain.
• Entrance effects matter in short tubes, and assuming fully developed flow where it is not is a common error.
• ⚠ Computational fluid dynamics will produce a plausible wrong answer. Turbulence models are approximations, mesh quality dominates, and boundary conditions decide the result. Hand calculation and measurement are what establish credibility — the same warning this repository makes about finite element analysis in the EML3011 and ETG3533C guides.

⚠ Florida makes thermal design distinctive

• Cooling load dominates. Building thermal design in Florida is a cooling problem, which inverts many of the intuitions in northern-authored textbooks and makes the HVAC market here unusually large.
• Latent load is a major share. Humidity removal consumes a substantial fraction of air conditioning energy in this climate, and psychrometric design matters more here than almost anywhere in the continental United States.
• Condensation and mould are design consequences. Surfaces below dew point condense, and in Florida that is a health and liability issue as well as an efficiency one — see this repository's guides on Florida building and mould regulation.
• Solar gain is large. Radiation through glazing and roof heat gain drive load; radiant barriers and reflective roofing have measurable payback here.
• Cooling water is warm. Higher ambient and water temperatures reduce condenser performance and plant efficiency, which is a real constraint on power generation in this state.
• Marine and coastal corrosion and biofouling attack heat exchangers aggressively; material selection matters more than in inland applications.
• Hurricane resilience affects equipment siting, elevation, and backup provision.
• The market consequence is that HVAC, refrigeration, and cold chain engineering are among the most reliable mechanical engineering employment in Florida.

⚠ An honest account of the workload

• Upper-division mechanical engineering courses demand sustained daily problem-solving and reward nothing else. Budget eight to twelve hours a week outside class.
• Work problems without the solution visible. Reading a worked example produces the feeling of understanding and none of the ability.
• Draw the diagram every time — free-body, control volume, thermal resistance network, or block diagram.
• State your assumptions explicitly. Steady state, incompressible, adiabatic, linear elastic, small angle — knowing which assumptions apply is most of the subject.
• Carry units through every step and check that the answer is physically plausible.
• Go to office hours in week two, not week ten. These courses are cumulative.

⚠ Institutional context — and check the number against the description

• This guide is written primarily from the University of West Florida catalog, which publishes a complete and unusually explicit set of EML entries. Other Florida institutions teaching this subject may number it differently.
• The EML prefix is not consistent across Florida. This repository has documented a genuine subject collision in the thermal-fluids sequence: EML3015 and EML3016 denote different subjects at UWF and at the FAMU-FSU College of Engineering — see the EML3015C and EML3016 guides.
• Much of the mechanical engineering core is also taught under the general engineering prefix EGN, and under SCNS those are different courses. Equivalency does not cross prefixes or a C or L suffix automatically.
• Identify a course by its catalog description, never by its number or its title.
• Give a receiving department the description rather than the course number when seeking a transfer determination, and get the answer in writing.

⚠ FE exam and PE licensure — this is the accredited engineering pathway

• This course sits inside an A.B.E.T.-EAC accredited engineering programme, the pathway that leads directly to professional licensure. That distinguishes it from engineering technology, where the route to a P.E. is longer — see this repository's ETG, EET, and ETC guides.
• Florida licenses professional engineers under Chapter 471, Florida Statutes, through the Florida Board of Professional Engineers: A.B.E.T.-EAC degree → FE examination → qualifying experience → PE examination → licensure.
• The NCEES FE Reference Handbook is free and is the only reference permitted in the exam. Use it as your working reference now so navigating it is automatic by exam day.
• Most students sit the FE in their final year, and pass rates are markedly higher for recent graduates than for those who wait.
• Only a licensed P.E. may offer engineering services to the public in Florida, seal drawings, or use the title in a way implying licensure.
• Rule 11 applies — verify current requirements with FBPE and NCEES directly.

How Florida course levels affect transfer

The first digit of an SCNS number denotes the year of offering, not transferability. Courses at the 1000 and 2000 levels transfer transparently between Florida public institutions, and 3000 to 4000 is unproblematic since both are upper division. The boundary that actually matters is 2000 to 3000, where lower-division credit generally cannot satisfy an upper-division requirement.

EML3703 is 3 semester hours and approximately 45 contact hours, and it completes the UWF thermal-fluids sequence. Expect a design project alongside problem work — the catalog names design explicitly, and it is what makes the course valuable.

Keep the design project. A documented thermal system design with selection calculations, a pump curve intersection, and an economic justification is genuine portfolio material for an HVAC, energy, or process engineering interview.