Three charts, the calculation method and the error list: the bottom of the window tells what the turbine is worth.

Overview: Hydro Turbine design

The bottom of the window holds three tabs: the results, which show where the head goes and how much reaches the shaft; the method, which explains the computation; and the errors, to be read before anything else.

Contents:

• Results: heads, powers, efficiencies
• Calculation method and Errors tab

Results: heads, powers, efficiencies

• Heads: the gross head split into the losses of the penstock, the casing, the distributor, the junction, the elbow and the draft tube, their sum (path losses), and the head absorbed by the runner.
• Power, at the current flow: maximum site power, available power, axial kinetic power, shaft power (computed or not).
• Efficiency: path efficiency Hn/Hb; shaft power / available power; shaft power / maximum site power.

The runner head counts the static Δp and the recovered swirl share; the residual swirl at the outlet is counted as a loss.

Calculation method and Errors tab

Method: the runner is computed by Heliciel, with blade element theory in penstock mode; the window computes everything around it and closes the Bernoulli balance of the water path. The head is a pressure: the runner receives Hn = Hb − path losses. The Betz limit, specific to a propeller in free stream, does not apply to a runner in a conduit. The tab also details the runner energy balance with the distributor swirl, and the complete course of a study.

Errors: the tab must be empty before reading any result. Each message points to the setting to correct.

Going further

The Hydro Turbine design reference page presents the complete method and a worked case. The other help pages of the window:

• Control panel
• Layout
• Spiral casing
• Distributor
• Runner
• Draft tube
• Specific speed
• Statistics
• Views and piezometric graph
• Fabrication kit
• Results, method, errors