# Linear Transport Relations (LTR)

Much of Transport Phenomena deals with the exchange of momentum, mass, or heat between two (or many) objects. Often, the most mathematically simple way to consider how and how fast exchanges take place is to look at driving forces and resistances.

In momentum transport, we are interested in driving forces that arise from differences in pressure and/or velocity.

• Solve problems in fluid hydrostatics
• Derive the pressure field equation [2.1]
• Calculate the pressure distribution in a fluid or system of fluids that is at rest [2.2]
• Use Archimedes' principle to calculate buoyant forces on (partially) immersed objects [2.3-2.4]
• Use friction factors and/or drag coefficients to calculate drag [12.2, 13.2-13.4]
• Distinguish between lift, drag, skin friction, and form drag
• Calculate friction factors from correlations and read friction factors off of charts
• Use friction factors and/or drag coefficients to calculate drag on submersed objects (external flows)
• Estimate friction losses in pipes and pipe networks

In heat and mass transport, our driving forces arise from differences in concentration and temperature.

• Perform convection and convection/radiation problems
• Perform convective heat transfer calculations [15.3, 19.1, 19.2]
• Perform convective mass transfer calculations [24.3, 28.1, 28.2]
• Perform radiative heat transfer calculations [15.4, 23.1, 23.2, (23.7)]
• Calculate the thermal resistance and magnitude of heat flow in combined convective/radiative systems [15.5]