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From dust devil to sustainable swirling wind energy.

Zhang M, Luo X, Li T, Zhang L, Meng X, Kase K, Wada S, Yu CW, Gu Z - Sci Rep (2015)

Bottom Line: Here, a concept of sustained dust-devil-like whirlwind is proposed for the energy generation.A prototype of a circular shed with pre-rotation vanes has been devised to generate the whirlwind flow by heating the air inflow into the circular shed.The pre-rotation vanes can provide the air inflow with angular momentum.

View Article: PubMed Central - PubMed

Affiliation: School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.

ABSTRACT
Dust devils are common but meteorologically unique phenomena on Earth and on Mars. The phenomenon produces a vertical vortex motion in the atmosphere boundary layer and often occurs in hot desert regions, especially in the afternoons from late spring to early summer. Dust devils usually contain abundant wind energy, for example, a maximum swirling wind velocity of up to 25 m/s, with a 15 m/s maximum vertical velocity and 5 m/s maximum near-surface horizontal velocity can be formed. The occurrences of dust devils cannot be used for energy generation because these are generally random and short-lived. Here, a concept of sustained dust-devil-like whirlwind is proposed for the energy generation. A prototype of a circular shed with pre-rotation vanes has been devised to generate the whirlwind flow by heating the air inflow into the circular shed. The pre-rotation vanes can provide the air inflow with angular momentum. The results of numerical simulations and experiment illustrate a promising potential of the circular shed for generating swirling wind energy via the collection of low-temperature solar energy.

No MeSH data available.


Related in: MedlinePlus

Dust devil occurring in nature, and configuration of a steady dust devil-like whirlwind producing system.(a), Evolution of a dust devil in nature. The near-surface air layer, heated by the hot ground (heat driven by solar radiation), becomes warm which may gradually lead to instability since this warm air layer is covered with a layer of cold air. The layer of air cannot turn around completely, thus, a convective plume forms at the center of the rising convection. As the convective plume rises to higher altitudes, the low pressure at its base deepens. This near-surface low-pressure center forces a spiral inflow of warm boundary layer air into the incipient dust devil. The swirling energy increases at the center, and then a dust devil emerges. (b), Design of the solar-energy-collecting shed for steady swirling airflows. The circular shed has pre-rotation vanes around the perimeter. As the shed is heated, the surrounding air flowing through the channels between the pre-rotation vanes becomes a swirling buoyant jet at the central outlet.
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f1: Dust devil occurring in nature, and configuration of a steady dust devil-like whirlwind producing system.(a), Evolution of a dust devil in nature. The near-surface air layer, heated by the hot ground (heat driven by solar radiation), becomes warm which may gradually lead to instability since this warm air layer is covered with a layer of cold air. The layer of air cannot turn around completely, thus, a convective plume forms at the center of the rising convection. As the convective plume rises to higher altitudes, the low pressure at its base deepens. This near-surface low-pressure center forces a spiral inflow of warm boundary layer air into the incipient dust devil. The swirling energy increases at the center, and then a dust devil emerges. (b), Design of the solar-energy-collecting shed for steady swirling airflows. The circular shed has pre-rotation vanes around the perimeter. As the shed is heated, the surrounding air flowing through the channels between the pre-rotation vanes becomes a swirling buoyant jet at the central outlet.

Mentions: A consensus has been reached on how dust devils are formed. The ambient vertical vorticity (angular momentum) combined with a vertical motion due to heat buoyancy (solar radiation) is the main mechanism for developing the phenomenon. When a net circulation of wind flow exists around the perimeter of an area, a buoyant convection within that area can occur that would strengthen the circulation and increase the local vorticity by stretching the wind flow89101112, as illustrated in Fig. 1a. Since both heat buoyancy and ambient vorticity tend to be unsustained in nature, the occurrences of dust devils are consequently random and short-lived.


From dust devil to sustainable swirling wind energy.

Zhang M, Luo X, Li T, Zhang L, Meng X, Kase K, Wada S, Yu CW, Gu Z - Sci Rep (2015)

Dust devil occurring in nature, and configuration of a steady dust devil-like whirlwind producing system.(a), Evolution of a dust devil in nature. The near-surface air layer, heated by the hot ground (heat driven by solar radiation), becomes warm which may gradually lead to instability since this warm air layer is covered with a layer of cold air. The layer of air cannot turn around completely, thus, a convective plume forms at the center of the rising convection. As the convective plume rises to higher altitudes, the low pressure at its base deepens. This near-surface low-pressure center forces a spiral inflow of warm boundary layer air into the incipient dust devil. The swirling energy increases at the center, and then a dust devil emerges. (b), Design of the solar-energy-collecting shed for steady swirling airflows. The circular shed has pre-rotation vanes around the perimeter. As the shed is heated, the surrounding air flowing through the channels between the pre-rotation vanes becomes a swirling buoyant jet at the central outlet.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321178&req=5

f1: Dust devil occurring in nature, and configuration of a steady dust devil-like whirlwind producing system.(a), Evolution of a dust devil in nature. The near-surface air layer, heated by the hot ground (heat driven by solar radiation), becomes warm which may gradually lead to instability since this warm air layer is covered with a layer of cold air. The layer of air cannot turn around completely, thus, a convective plume forms at the center of the rising convection. As the convective plume rises to higher altitudes, the low pressure at its base deepens. This near-surface low-pressure center forces a spiral inflow of warm boundary layer air into the incipient dust devil. The swirling energy increases at the center, and then a dust devil emerges. (b), Design of the solar-energy-collecting shed for steady swirling airflows. The circular shed has pre-rotation vanes around the perimeter. As the shed is heated, the surrounding air flowing through the channels between the pre-rotation vanes becomes a swirling buoyant jet at the central outlet.
Mentions: A consensus has been reached on how dust devils are formed. The ambient vertical vorticity (angular momentum) combined with a vertical motion due to heat buoyancy (solar radiation) is the main mechanism for developing the phenomenon. When a net circulation of wind flow exists around the perimeter of an area, a buoyant convection within that area can occur that would strengthen the circulation and increase the local vorticity by stretching the wind flow89101112, as illustrated in Fig. 1a. Since both heat buoyancy and ambient vorticity tend to be unsustained in nature, the occurrences of dust devils are consequently random and short-lived.

Bottom Line: Here, a concept of sustained dust-devil-like whirlwind is proposed for the energy generation.A prototype of a circular shed with pre-rotation vanes has been devised to generate the whirlwind flow by heating the air inflow into the circular shed.The pre-rotation vanes can provide the air inflow with angular momentum.

View Article: PubMed Central - PubMed

Affiliation: School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.

ABSTRACT
Dust devils are common but meteorologically unique phenomena on Earth and on Mars. The phenomenon produces a vertical vortex motion in the atmosphere boundary layer and often occurs in hot desert regions, especially in the afternoons from late spring to early summer. Dust devils usually contain abundant wind energy, for example, a maximum swirling wind velocity of up to 25 m/s, with a 15 m/s maximum vertical velocity and 5 m/s maximum near-surface horizontal velocity can be formed. The occurrences of dust devils cannot be used for energy generation because these are generally random and short-lived. Here, a concept of sustained dust-devil-like whirlwind is proposed for the energy generation. A prototype of a circular shed with pre-rotation vanes has been devised to generate the whirlwind flow by heating the air inflow into the circular shed. The pre-rotation vanes can provide the air inflow with angular momentum. The results of numerical simulations and experiment illustrate a promising potential of the circular shed for generating swirling wind energy via the collection of low-temperature solar energy.

No MeSH data available.


Related in: MedlinePlus