6
Heat and Mass Transfer Processes
Abstract
Heat and mass transfer principles, coupled with the modulation of energy and mass
budgets, were covered in this chapter. Transfer processes regulate a spectrum of
phenomena, such as variations of carbon and water exchanges or sediment
transport. The main topics related to heat conduction were Fourier’s law and the
thermal exchanges in the upper layers of soils, considering their influence in
stationary and transient processes. Natural and forced convection processes were
assessed through empirical parameters, ratios, and equations reflecting the
interactions between fluid mechanics, in air and water, and the transfer of heat,
particles, and molecules. Empirical tools for convection analysis considered the
prevalence of viscous and inertial forces, allowing also estimation of ratio between
depths of thermal and momentum boundary layers in objects. The fundamentals of
radiation emissivity, transmissivity, absorption, net radiation, and radiative spatial
relationships were also considered. The theoretical foundations and environmental
relevance of mass transfer of gases and particles and the importance of Brownian,
viscous, or Newtonian drag were also developed. The associated processes of
creeping, jumping, impaction or wet transfer, dependent on the balance of forces
such as friction, inertia, or gravity through the wind field and transport of
sediments in watercourses were highlighted.
6.1 Conduction
6.1.1 General Principles
Conduction is a key mechanism of heat transfer in environment microsystems. The
biosphere is a heat sink during heating periods (daytime, summer) and a source of
heat during the colder periods (night, winter). Thus, surface organic and inorganic
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
A. Rodrigues et al., Fundamental Principles of Environmental Physics,
https://doi.org/10.1007/978-3-030-69025-0_6
159
Heat and Mass Transfer Processes
Abstract
Heat and mass transfer principles, coupled with the modulation of energy and mass
budgets, were covered in this chapter. Transfer processes regulate a spectrum of
phenomena, such as variations of carbon and water exchanges or sediment
transport. The main topics related to heat conduction were Fourier’s law and the
thermal exchanges in the upper layers of soils, considering their influence in
stationary and transient processes. Natural and forced convection processes were
assessed through empirical parameters, ratios, and equations reflecting the
interactions between fluid mechanics, in air and water, and the transfer of heat,
particles, and molecules. Empirical tools for convection analysis considered the
prevalence of viscous and inertial forces, allowing also estimation of ratio between
depths of thermal and momentum boundary layers in objects. The fundamentals of
radiation emissivity, transmissivity, absorption, net radiation, and radiative spatial
relationships were also considered. The theoretical foundations and environmental
relevance of mass transfer of gases and particles and the importance of Brownian,
viscous, or Newtonian drag were also developed. The associated processes of
creeping, jumping, impaction or wet transfer, dependent on the balance of forces
such as friction, inertia, or gravity through the wind field and transport of
sediments in watercourses were highlighted.
6.1 Conduction
6.1.1 General Principles
Conduction is a key mechanism of heat transfer in environment microsystems. The
biosphere is a heat sink during heating periods (daytime, summer) and a source of
heat during the colder periods (night, winter). Thus, surface organic and inorganic
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
A. Rodrigues et al., Fundamental Principles of Environmental Physics,
https://doi.org/10.1007/978-3-030-69025-0_6
159