namespace Yw.Epanet
{
    /// <summary>
    /// 计算辅助类
    /// </summary>
    public class CalcuHelper
    {

        /// <summary>
        /// 计算流速 m/s
        /// </summary>
        /// <param name="flow">流量m³/h</param>
        /// <param name="diameter">直径 mm</param>
        /// <returns>流速 m/s</returns>
        public static double CalcuVelocity(double flow, double diameter)
        {
            if (diameter <= 0)
            {
                return default;
            }

            // 单位转换
            var q = flow / 3600;// m³/h → m³/s
            var d = diameter / 1000; // mm → m
            // 计算横截面积
            var a = Math.PI * Math.Pow(d, 2) / 4;
            // 计算流速 (m/s)
            double velocity = q / a;
            return velocity;
        }

        /// <summary>
        /// 计算局部损失
        /// </summary>
        /// <param name="k">损失系数</param>
        /// <param name="velocity">流速m/s</param>
        /// <returns>局部损失 m</returns>
        public static double CalcuMinorLoss(double k, double velocity)
        {
            return k * Math.Pow(Math.Abs(velocity), 2) / (2 * ConstParas.g);
        }

        /// <summary>
        /// 计算能量
        /// </summary>
        /// <param name="flow">流量 m³/h</param>
        /// <param name="head">水头 m</param>
        /// <returns>能量 w</returns>
        public static double CalcuEnergy(double flow, double head)
        {
            var energy = Math.Abs(flow * head);
            energy = energy * ConstParas.WaterDensity * ConstParas.g / 3600;
            return energy;
        }



    }
}