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Upwind_downwind_example.png (500 × 300 pixels, file size: 33 KB, MIME type: image/png) This is a file from the Wikimedia Commons . Information from its description page there is shown below.
Windward is upwind from the point of reference, i.e., towards the direction from which the wind is coming; leeward is downwind from the point of reference, i.e., along the direction towards which the wind is going. The side of a ship that is towards the leeward is its "lee side".
Upwind leg. A flight path parallel to and in the direction of the landing runway. It is offset from the runway and opposite the downwind leg. Crosswind leg. A short climbing flight path at right angles to the departure end of the runway. Downwind leg. A long level flight path parallel to but in the opposite direction of the landing runway.
Downwind machines have been built, because they don't need an additional mechanism for keeping them in line with the wind. In high winds, downwind blades can also be designed to bend more than upwind ones, which reduces their swept area and thus their wind resistance, mitigating risk during gales.
A vehicle with a bladed rotor mechanically connected to the wheels can be designed to go at a speed faster than that of the wind, both directly into the wind and directly downwind. Upwind, the rotor works as a wind turbine driving the wheels. Downwind, it works as a propeller, driven by the wheels. In both cases, power comes from the difference ...
This imposes limitations on the amount of fuel carried and the order in which fuel must be used. Turbine engines burn fuel faster than reciprocating engines do. Because fuel needs to be injected in to a combustor, the injection system of a turbine aircraft must provide fuel at higher pressure and flow compared to that for a piston engine aircraft.
A turbine map [1] shows lines of percent corrected speed (based on a reference value) plotted against the x-axis which is pressure ratio, but deltaH/T (roughly proportional to temperature drop across the unit/component entry temperature) is also often used. The y-axis is some measure of flow, usually non-dimensional flow or corrected flow, but ...
The French wind turbine manufacturer Vergnet has several medium and large self-orienting downwind wind turbines in production. Passive yaw systems have to be designed in a way that the nacelle does not follow the sudden changes in wind direction with too fast a yaw movement, in order to avoid high gyroscopic loads.