RND_EDGE_MESH

Overview

Calculate the loss coefficient for a round edged open net or screen mesh.

Excel Usage

=RND_EDGE_MESH(alpha, mesh_type, angle)

• alpha (float, required): Fraction of net/screen open to flow, [-]
• mesh_type (str, optional, default: “diamond pattern wire”): Type of mesh pattern
• angle (float, optional, default: 0): Angle of inclination (0 = straight, 90 = parallel to flow), [degrees]

Returns (float): Loss coefficient K, [-], or error message (str) if input is invalid.

Examples

Example 1: Diamond pattern wire (alpha=0.96)

Inputs:

alpha
0.96

Excel formula:

=RND_EDGE_MESH(0.96)

Expected output:

0.0289

Example 2: With angle (alpha=0.96, angle=33)

Inputs:

alpha	angle
0.96	33

Excel formula:

=RND_EDGE_MESH(0.96, 33)

Expected output:

0.0203

Example 3: Round bar screen (alpha=0.9)

Inputs:

alpha	mesh_type
0.9	round bar screen

Excel formula:

=RND_EDGE_MESH(0.9, "round bar screen")

Expected output:

0.097

Example 4: Knotted net (alpha=0.95)

Inputs:

alpha	mesh_type
0.95	knotted net

Excel formula:

=RND_EDGE_MESH(0.95, "knotted net")

Expected output:

0.0473

Python Code

from fluids.filters import round_edge_open_mesh as fluids_round_edge_open_mesh

def rnd_edge_mesh(alpha, mesh_type='diamond pattern wire', angle=0):
    """
    Calculate the loss coefficient for a round edged open net or screen mesh.

    See: https://fluids.readthedocs.io/fluids.filters.html#fluids.filters.round_edge_open_mesh

    This example function is provided as-is without any representation of accuracy.

    Args:
        alpha (float): Fraction of net/screen open to flow, [-]
        mesh_type (str, optional): Type of mesh pattern Valid options: Diamond Pattern Wire, Round Bar Screen, Knotted Net, Knotless Net. Default is 'diamond pattern wire'.
        angle (float, optional): Angle of inclination (0 = straight, 90 = parallel to flow), [degrees] Default is 0.

    Returns:
        float: Loss coefficient K, [-], or error message (str) if input is invalid.
    """
    try:
      # Validate and convert alpha
      try:
        alpha = float(alpha)
      except (ValueError, TypeError):
        return "Error: alpha must be a number."

      # Validate and convert angle
      try:
        angle = float(angle)
      except (ValueError, TypeError):
        return "Error: angle must be a number."

      # Validate ranges
      if alpha < 0.85 or alpha > 1:
        return "Error: alpha must be between 0.85 and 1."
      if angle < 0 or angle > 90:
        return "Error: angle must be between 0 and 90 degrees."

      # Validate mesh_type
      valid_types = ['round bar screen', 'diamond pattern wire', 'knotted net', 'knotless net']
      if mesh_type not in valid_types:
        return f"Error: mesh_type must be one of {valid_types}."

      result = fluids_round_edge_open_mesh(alpha=alpha, subtype=mesh_type, angle=angle)
      if result != result or result in (float('inf'), float('-inf')):
        return "Error: Result is not finite."
      return float(result)
    except Exception as e:
      return f"Error: {str(e)}"

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