# 4.10. Boundary Conditions

Every exposed surface in your mesh must have a sideset on it, and every sideset must have a boundary condition applied. Fuego will throw an error at runtime if these conditions are not met. Boundary conditions are specified in the `Fuego Region` block, and the available options are described in this section.

- 4.10.1. Open
  - 4.10.1.1. Entrained Momentum
  - 4.10.1.2. Entrained Turbulence Quantities
  - 4.10.1.3. Total Pressure
  - 4.10.1.4. Sponge Layer
- 4.10.2. Inflow
  - 4.10.2.1. Use Fluxes
- 4.10.3. Wall
  - 4.10.3.1. Turbulent Wall Modeling
  - 4.10.3.2. Post-Processing
  - 4.10.3.3. Conjugate Heat Transfer
  - 4.10.3.4. Convection Coefficients
- 4.10.4. Wall Mass Inject
  - 4.10.4.1. Specified Injection
  - 4.10.4.2. Pool Model
- 4.10.5. Symmetry
- 4.10.6. Periodic
- 4.10.7. Mass Flux
- 4.10.8. Composite
  - 4.10.8.1. 1D Composite Model
  - 4.10.8.2. Composite Interface
- 4.10.9. Fixed
- 4.10.10. Heat Flux
- 4.10.11. Non-Conformal