Thread: Article Sky Angel 50mm EDFs Review
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Old Jan 21, 2013, 04:56 PM
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Measuring efflux speed directly has been difficult for me in the past as the as the measurement varies depending where you place the probe and also there can be swirl in the flow as well so you have to take many reading and average. I found it much easier to calculate an average efflux value based on measured thrust and the outlet diameter. But once you have that value what do your really do with it? If you have a fixed outlet diameter then higher efflux = more thrust but you already know that as you measured thrust so you know the efflux will be automatically higher. The only time I used the efflux values was when I did a drag polar on a model to try and predict top speed. Having the efflux speed allowed me to predict how thrust drops off with forward speed and top speed was reached when thrust = model drag. These days I prefer to just fly and see what I get
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