def METHOD_NAME(comp_str):
    """Return whether a viscosity model is available for a component.
    Args:
        comp_str (str): component string
    Returns:
        bool: True if viscosity model is available, False if not
    """
    comp_str = comp_str.lower()
    if component_registered(comp_str):
        return _components[comp_str].viscosity
    return False