Tutorial1 Text
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Model Solutions to Tutorial Sheet 1 – Transliteration of Hand-written Notes! Q1 For discussion only… following notes apply (a) At constant speed there is no change with time of the oncoming airflow relative to the aircraft structure. The flow field is therefore time-independent (i.e. steady). However there may be turbulent regions near parts of the airframe where flow separation has taken place (eg. In the wake behind the wings)…turbulent regions are time dependant (hence unsteady). Flow past the wing sections is principally (and ideally) two dimensional - over parts such as the fuselage it is clearly three-dimensional. (b) Flow is mainly two dimensional in the central part of the weir but near to its ends (the ‘piers’ it is clearly three-dimensional. For one hour on a particular day, the flow can be regarded as steady… changes with time (such as variations in river depth) occur over much longer time scales. (c) Low flow rate: a laminar ribbon of water comes out of the tap. Laminar is steady because the geometry of the ribbon does not change and there are no fluctuations. Higher flow rate: jet of water is turbulent therefore flow is unsteady. Both are three-dimensional flows (but the laminar has axi- symmetry)
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Transcript of Tutorial1 Text
Model Solutions to Tutorial Sheet 1
Model Solutions to Tutorial Sheet 1 Transliteration of Hand-written Notes!Q1 For discussion only following notes apply
(a) At constant speed there is no change with time of the oncoming airflow relative to the aircraft structure. The flow field is therefore time-independent (i.e. steady). However there may be turbulent regions near parts of the airframe where flow separation has taken place (eg. In the wake behind the wings)turbulent regions are time dependant (hence unsteady).
Flow past the wing sections is principally (and ideally) two dimensional - over parts such as the fuselage it is clearly three-dimensional.
(b) Flow is mainly two dimensional in the central part of the weir but near to its ends (the piers it is clearly three-dimensional.
For one hour on a particular day, the flow can be regarded as steady changes with time (such as variations in river depth) occur over much longer time scales.(c) Low flow rate: a laminar ribbon of water comes out of the tap. Laminar is steady because the geometry of the ribbon does not change and there are no fluctuations.
Higher flow rate: jet of water is turbulent therefore flow is unsteady.
Both are three-dimensional flows (but the laminar has axi-symmetry)
