Length Of Strainer Given Discharge Calculator

Strainer Length Formula:

\[ lst = \frac{Q \cdot \log\left(\frac{R_w}{r}, 10\right)}{2.72 \cdot K_{WH} \cdot S_{tw}} - \frac{S_{tw}}{2} \]

Discharge (Q):

m³/s

Radius of Influence (R_w):

Radius of Well (r):

Coefficient of Permeability (K_WH):

m/s

Total Drawdown (S_tw):

Strainer Length (lst):

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1. What is the Strainer Length Formula?

The Strainer Length formula calculates the required length of a well strainer based on discharge, radius parameters, permeability coefficient, and total drawdown. This is essential in well hydraulics for proper well design and efficient water extraction.

2. How Does the Calculator Work?

The calculator uses the strainer length formula:

\[ lst = \frac{Q \cdot \log\left(\frac{R_w}{r}, 10\right)}{2.72 \cdot K_{WH} \cdot S_{tw}} - \frac{S_{tw}}{2} \]

Where:

\( lst \) — Strainer Length (m)
\( Q \) — Discharge (m³/s)
\( R_w \) — Radius of Influence (m)
\( r \) — Radius of Well (m)
\( K_{WH} \) — Coefficient of Permeability (m/s)
\( S_{tw} \) — Total Drawdown (m)

Explanation: The formula accounts for the logarithmic relationship between radius ratio and the hydraulic parameters to determine optimal strainer length.

3. Importance of Strainer Length Calculation

Details: Proper strainer length calculation is crucial for efficient well performance, preventing sand intrusion, maximizing water yield, and ensuring long-term well sustainability.

4. Using the Calculator

Tips: Enter all values in appropriate units (meters for lengths, m³/s for discharge, m/s for permeability). All values must be positive and non-zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the radius ratio in the formula?
A: The radius ratio (R_w/r) represents the influence zone of the well and affects the flow characteristics around the well screen.

Q2: Why is the permeability coefficient important?
A: The permeability coefficient determines how easily water flows through the aquifer material, directly impacting the required strainer length.

Q3: What is total drawdown and how is it measured?
A: Total drawdown is the difference between static water level and pumping water level, typically measured during pumping tests.

Q4: Are there limitations to this formula?
A: This formula assumes homogeneous aquifer conditions and may need adjustments for layered or anisotropic aquifers.

Q5: How does strainer length affect well performance?
A: Proper strainer length ensures optimal water entry velocity, minimizes head losses, and prevents sediment entry while maximizing yield.