Fully developed circular-pipe model
Round-Duct Straight-Run Pressure Loss
Calculate distributed wall-friction loss for a straight constant-diameter circular duct with supplied fluid density, viscosity and absolute roughness. Transitional flow and unmodelled fittings are not guessed.
Straight-run result
一个 NREL/US DOE HVAC modelling presentation documents Darcy-Weisbach with laminar and turbulent friction-factor treatment. NASA defines Re=ρvL/μ as the inertial-to-viscous similarity parameter.
A NASA pipe-flow reference places transition usually between Re 2300 and 4000 depending on disturbances. No single regime equation is asserted in that interval, so this calculator reports it as out of scope. The DOE fluid-flow handbook notes viscosity is a fluid property affected by temperature.
已移除的声明： the former page hard-coded ρ=1.2 kg/m³ and μ=1.81×10⁻⁵ Pa·s without conditions, called a Haaland explicit approximation “Colebrook”, and applied it immediately above Re 2300. Unsourced roughness/velocity/equivalent-length presets and rectangular-duct shortcut were removed.
Nikolai Shelkovenko
Nikolai Shelkovenko是一名振动分析工程师，也是Vibromera的创始人兼首席执行官。 15年多来，他一直在现场——而非在试验台上——为旋转设备进行平衡：粉碎机、工业风机、破碎机、离心机、轴和主轴。正是这些实际工作催生了Balanset系列仪器——它们被设计为一种专业人员可以随身携带到机器旁、在现场独立使用的工具，而非实验室设备。 Vibromera成立于2017年，自2023年起总部设于葡萄牙波尔图。Balanset系列产品的研发、组装与支持均在此完成。旗舰产品是Balanset-1A，一款用于单平面及双平面平衡和振动诊断的便携式分析仪。 Nikolai亲自参与客户支持工作，处理各种棘手的平衡案例，并参与软件开发。他以任何语言为全球客户提供服务。
