The document discusses well hydraulics, focusing on Darcy's law, which describes fluid flow through porous media. It outlines concepts of groundwater flow, including both steady and unsteady conditions in confined and unconfined aquifers, as well as image well theory and partial penetration of wells. Objectives include identifying flow direction and measuring water discharge through permeability.

1. KONGUNADU COLLEGE OF ENGINEERING AND TECHNOLOGY
(AUTONOMOUS)
DEPARTMENT OF AGRICULTURE ENGINEERING
Course: Groundwater and Well Engineering
Topic : WELL HYDRAULICS
By
Mr. M.Sundharan,
Assistant Professor,
Department of Agricultural Engineering,
Kongunadu College of Engineering and Technology

2. DARCY’S LAW
• In fluid dyanamics and hydrogeology, Darcy’s
law is a phenominal derived constitutive
equation that describes the flow of a fluid
through the porous medium.
• The law was formulated by Henry Darcy in
1856 on the flow of water through beds of
sand.
(Filtration)

3. Principle:
Darcy’s law states the principle which governs the
movement of fluid in the given substance.
Darcy’s law equation describes the capability of
the liquid to flow via any porous media like a
rock.
The law is based on the fact according to, the
flow between two points is directly proportional
to the pressure differences between the points,
the distance, and the connectivity of flow within
rocks between the points.
Measuring the inter-connectivity is known as
permeability.

4. Objectives
 Able to identify the direction of flow
 Able to measure the amount of water
discharge through permeability

5. Darcy’s law equation

8. Flow of Fluids

9. Aquifers

10. Groundwater Flow Equation
Important Symbols Used in Groundwater Flow
 b - Aquifer thickness
 h - Piozometric head
 K - Hydraulic Conductivity
 S - Storage co-efficient
 Ss - Specific stoarage
 T - Transmissibility
 t - Time
 X, Y, Z - Co-ordinate directions

11. Flow Concepts
A. Homogeneous Rocks
B. Heterogenous Rocks
i) Anisotropic Aquifer
ii) Isotropic Aquifer
1) Confined aquifer
2) Un-confined aquifer

12. Steady Groundwater Flow
Steady Flow in “Confined and Unconfined Aquifer”
Under the conditions of a steady flow in both the
“Confined and Unconfined Aquifer”, the level of
groundwater remain steady or constant over the
time.
It needs to be highlighted that when the rate of
discharge of groundwater is equal to the rate of
recharge of groundwater, then there can be
observed a steady flow in both confined and
unconfined aquifers.

13. Steady Flow Equation

16. Dupuit Forcheimer

19. Unsteady Groundwater Flow
 In both the confined and unconfined aquifer, an unsteady flow
refers to the condition where the quantity of groundwater
flowing per second does not remain always constant.
 Furthermore, from various researches, it can be observed that
an unsteady flow is considered as the “transient phenomenon”.
 As time passes the unsteady flow in both the confined and
unconfined aquifer can become zero or steady flow.
 On the other hand, in this type of flow, the rate of recharge of
groundwater is not equal to the rate of groundwater discharge.

20. Theis Method

21. Jacob method

22. Image Well Theory
• "Image well theory" in groundwater refers to a conceptual
approach used in hydrogeology to understand and model
the behavior of wells and groundwater flow systems,
particularly in the vicinity of boundaries and interfaces.
• The image well theory is based on the concept of
mirroring or "image" wells that are imagined to exist
across boundaries or interfaces. This theory is often used
in situations where the actual hydrogeological conditions
may not be straightforward due to the presence of
geological complexities.

23. Partial Penetration of wells
Partial penetration of wells refers to a situation
where the screened or perforated section of a
wellbore does not extend through the entire
thickness of the aquifer. Instead, the well
penetrates only a portion of the aquifer's
thickness.