CN211782995U

CN211782995U - Delta-wing vortex generator for unsteady incoming flow

Info

Publication number: CN211782995U
Application number: CN202020241678.XU
Authority: CN
Inventors: 刘鑫
Original assignee: Lanzhou Jiaotong University
Current assignee: Lanzhou Jiaotong University
Priority date: 2020-03-03
Filing date: 2020-03-03
Publication date: 2020-10-27
Anticipated expiration: 2030-03-03

Abstract

The utility model belongs to reinforce the heat transfer field, more specifically says, in particular to delta wing vortex generator of unsteady incoming flow. The vortex generator is made of elastic materials, and a gap is arranged at the tail part of the vortex generator, so that the tail part of the vortex generator can swing within a certain angle, and when incoming flow exists, the vortex generator can vibrate; the vortex generator is positioned behind the fluid channel, and when incoming flow exists, the overturning sheet can overturn and supply the incoming flow with periodical speed change to the rear side of the vortex generator. The heat exchanger has the characteristics of unsteady incoming flow, simple stamping die, low manufacturing cost, high heat exchange efficiency and good compactness.

Description

Delta-wing vortex generator for unsteady incoming flow

Technical Field

The utility model belongs to reinforce the heat transfer field, more specifically says, in particular to delta wing vortex generator of unsteady incoming flow.

Background

With the progress of science and technology, people are pursuing simpler and more efficient heat exchangers. In production life, heat exchangers exchange heat mainly through two most basic heat transfer modes of heat conduction and heat convection, and heat conduction performance mainly depends on the property of materials, so that how to enhance the heat exchange efficiency of the convection side of the heat exchanger becomes a problem to be solved by researchers. At present, the vortex generator is arranged on the heat exchange surface, which is a way to effectively improve the heat exchange efficiency of the heat exchange surface.

To further enhance the convective heat transfer properties to the solid wall surface, the structure of the vortex generator can be modified.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a triangle wing vortex generator of unsteady incoming flow has unsteady incoming flow, and stamping die is simple moreover, low in manufacturing cost is honest and clean, heat exchange efficiency is high and the characteristics that the compactedness is good to solve the problem that proposes in the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

an unsteady incoming flow delta wing vortex generator comprises a solid wall surface and a vortex generator, wherein the vortex generator is triangular and is vertically arranged on the solid wall surface, an included angle theta between the bottom edge of the vortex generator and the incoming flow direction is 30-70 degrees, the vortex generator is made of an elastic material, and a notch is formed in the tail part of the vortex generator, so that the tail part of the vortex generator can swing within a certain angle, and when incoming flow exists, the vortex generator can vibrate;

the vortex generator is positioned behind the fluid channel, and when incoming flow exists, the turnover sheet can turn over and periodically give the back to the vortex generator, so that the incoming flow of the vortex generator is generated. The incoming flow passes through the variable flow rate mechanism, the wafer can start to deflect under the comprehensive action of pressure difference and impact force, and can deviate from a balance position to continuously deflect due to inertia of the wafer, so that the flow rate of the fluid behind the fluid channel is continuously changed.

Furthermore, the fluid channel is in a shape of a circular tube, two small holes are symmetrically formed in the wall of the circular tube, the turnover piece is composed of a circular sheet and a turnover shaft penetrating through the center of the circular sheet, two ends of the turnover shaft penetrate through the small holes and can rotate in the small holes to drive the circular sheet to rotate, and the diameter of the part, located outside the fluid channel, of the turnover shaft is larger than that of the small holes. Before use, the turnover sheet is shifted in advance to enable the included angle between the turnover sheet and the incoming flow direction to be not 90 degrees or 0 degrees, and the turnover shaft can rotate smoothly.

Further, the disc and the overturning shaft are integrally formed.

Furthermore, the notch is positioned at the bottom end of the tail of the vortex generator, the height of the notch is 0.2-0.4 times of the height of the vortex generator, and the length of the notch is 0.4-0.6 times of the length of the bottom edge of the vortex generator. Through experiments, the vortex generator designed by the parameters has better heat exchange performance.

Further, the thickness of the vortex generator is 0.01-0.05 mm. Through experiments, the vortex generator with the thickness is easier to generate vibration.

Furthermore, the vortex generators are arranged along the gas flow direction in a sequential or staggered manner. The front part of the vortex generator is firstly contacted with fluid, and the design can generate pressure difference between the front end and the rear end of the vortex generator to form vortex. The vortex generators can adopt different arrangement modes and can participate in the process of heat exchange enhancement. The parallel arrangement has lower resistance to gas flow, but has insufficient impact on the heat exchange wall surface, and the staggered arrangement has higher resistance to gas flow, so that the impact on the heat exchange wall surface can be improved.

Furthermore, the material of the vortex generator is aluminum or copper. The material is commonly used and easy to produce and manufacture.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the utility model discloses a set up the breach to the vortex generator for the vortex generator afterbody has the effect that can vibrate, thereby improves heat exchange efficiency. The principle is that under the action of fluid scouring and the elasticity of the vortex generator, the vortex generator generates longitudinal vortex to strengthen heat exchange, and simultaneously vibrates, so that the disturbance of surrounding fluid is increased, and the heat exchange efficiency is improved.

When flowing through the vortex generator, the fluid can generate longitudinal vortex in the flow channel, so that the boundary layer is thinned, the fluid disturbance is increased, the mutual mixing of cold fluid and hot fluid is promoted, and the heat exchange coefficient of the solid wall surface is improved.

Meanwhile, when fluid flushes the vortex generator, pressure difference can be generated in front of and behind the vortex generator, and the pressure difference enables the rear portion of the vortex generator to be bent, so that flowing resistance can be reduced. When the vortex generator is bent by the scouring of the fluid, the vortex generator can keep a certain bending degree when the flow in the heat exchanger channel is stable due to the elasticity of the material of the vortex generator; when the flow is unstable, the vortex generator rebounds, vibrates under the action of the elasticity and the pressure difference of the vortex generator, and the continuous vibration of the vortex generator disturbs the fluid, so that the turbulence degree of the fluid flow is increased, and the heat exchange of the solid wall surface is strengthened.

Therefore, the longitudinal vortex generated by the vortex generator strengthens the heat exchange of the rear area of the vortex generator. The vibrating vortex generator can reduce the flowing resistance when being bent, and can further enhance the convection heat exchange performance of the solid wall surface on the basis of keeping the advantage of heat exchange enhancement of the vortex generator.

2. Through setting up variable flow rate mechanism, the incoming flow passes through variable flow rate mechanism earlier, and the wafer can begin to deflect under the combined action of pressure differential and impact force, has inertia because of its self again, can deviate from the balanced position and continuously deflect, continuously changes the fluid flow rate behind the fluid passage. Specifically, the variable flow rate mechanism can make the fluid speed on the cross section change periodically, thereby obtaining unsteady incoming flow. Because when the flow is stable, the elasticity of the vortex generator and the front-back pressure difference of the vortex generator are balanced, the vortex generator can keep a certain curvature, and then the vortex generator tends to be in a stable state, and the vibration effect is poor. Through setting up variable flow rate mechanism for the incoming flow is unstable, can improve the vibration effect of vortex generator afterbody under the effect of fluid impact force and self elasticity.

3. The utility model discloses the practicality is high, and in practical application, the operating mode of heat exchanger is changeable, and the speed of incoming flow is not invariable, adopts the vortex generator of fixed pattern can not guarantee the heat transfer performance under operating mode, uses the triangle wing vortex generator that can vibrate, and the form of vortex generator can change along with the change of incoming flow, more presses close to engineering reality; meanwhile, the vortex generator vibrates, so that the vortex generator has certain cleaning effect, and the heat transfer deterioration of the heat exchange surface caused by dust accumulation and oil stain adhesion is reduced

Drawings

FIG. 1 is a schematic view of the vortex generator of the present invention fixed to a solid wall;

FIG. 2 is a side view of the delta-wing vortex generator of the present invention with unsteady incoming flow;

FIG. 3 is a schematic structural view of the variable flow rate mechanism of the present invention

In the figure: 1. a solid wall surface; 2. a vortex generator; 201. a notch; 3. a fluid channel; 4. a wafer; 5. a turning shaft; 6. and a variable flow rate mechanism.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-3, an unsteady incoming flow delta-wing vortex generator includes a solid wall surface 1 and a vortex generator 2, wherein the vortex generator 2 is disposed on the solid wall surface 1, a gap 201 is disposed at a tail of the vortex generator 2, the vortex generator 2 is made of an elastic material, the gap 201 enables the tail of the vortex generator 2 to swing within a certain angle, and the vortex generator 2 can vibrate when there is an incoming flow, and further includes a variable flow rate mechanism 6 disposed on the solid wall surface 1;

the variable flow rate mechanism 6 comprises a fluid channel 3 and an overturning sheet which is arranged in the fluid channel 3 and can be overturned, the vortex generator 2 is positioned behind the fluid channel 3, and when incoming flow exists, the overturning sheet can be overturned and periodically gives the incoming flow to the vortex generator 2 behind. The incoming flow passes through the variable flow rate mechanism 6, the wafer 4 starts to deflect under the combined action of pressure difference and impact force, and can continuously deflect beyond the balance position due to inertia of the wafer, so that the flow rate of the fluid behind the fluid channel 3 is continuously changed.

In a preferred scheme, the fluid channel 3 is in a shape of a circular tube, two small holes are symmetrically formed in the wall of the circular tube, the turnover piece is composed of a circular sheet 4 and a turnover shaft 5 penetrating through the center of the circular sheet 4, two ends of the turnover shaft 5 penetrate through the small holes and can rotate in the small holes so as to drive the circular sheet 4 to rotate, and the diameter of the part, located outside the fluid channel 3, of the turnover shaft 5 is larger than that of the small holes. Before use, the turnover sheet is shifted in advance to enable the included angle between the turnover sheet and the incoming flow direction to be not 90 degrees or 0 degrees, and the turnover shaft can rotate smoothly.

In a preferred embodiment, the disc 4 and the tumble shaft 5 are integrally formed.

In a preferred embodiment, the vortex generators 2 are triangular. The front part of the vortex generator 2 is firstly contacted with fluid, and the design can generate pressure difference between the front end and the rear end of the vortex generator 2 to form vortex.

In a preferred embodiment, the notch 201 is located at the bottom end of the tail of the vortex generator 2, the height of the notch 201 is 0.2-0.4 times the height of the vortex generator 2, and the length of the notch 201 is 0.4-0.6 times the length of the bottom edge of the vortex generator 2. Through experiments, the vortex generator 2 designed by adopting the parameters has better heat exchange performance.

In a preferred embodiment, the thickness of the vortex generator 2 is 0.01-0.05 mm. Through experiments, the vortex generator 2 with the thickness is easier to generate vibration.

In a preferred embodiment, the vortex generators 2 are arranged along the gas flow direction in a row or a fork row. The vortex generators 2 can adopt different arrangement modes and can participate in the process of heat exchange enhancement. The parallel arrangement has lower resistance to gas flow, but has insufficient impact on the heat exchange wall surface, and the staggered arrangement has higher resistance to gas flow, so that the impact on the heat exchange wall surface can be improved.

In a preferred embodiment, the material of the vortex generator 2 is aluminum or copper. The material is commonly used and easy to produce and manufacture.

The working principle is as follows: the vortex generator 2 is arranged on the solid wall surface 1 in a staggered mode, the variable flow rate mechanism 6 is arranged in front of the vortex generator 2, the wafer 4 in the channel is stirred in advance, when uniform incoming flow exists in the fluid channel 3, the wafer can start to deflect under the comprehensive action of pressure difference and impact force, and can deviate from a balance position to continuously deflect due to inertia of the wafer, so that the flow rate of the downstream fluid is continuously changed; specifically, the variable flow rate mechanism 6 can make the fluid speed on the cross section change periodically, thereby generating unstable incoming flow;

when the fluid flows through the vortex generator 2, pressure difference exists in front of and behind the vortex generator 2, the flowing direction of the fluid is changed under the action of the pressure difference, secondary vortex is generated above the solid wall surface 1, exchange between hot fluid close to the solid wall surface 1 and cold fluid of the incoming fluid is accelerated by the secondary vortex, and therefore the convection heat exchange of the secondary vortex through the area solid wall surface 1 is strengthened. Meanwhile, under the action of the front-back pressure difference of the vortex generator 2, the part of the vortex generator 2 disconnected with the fins, namely the tail part of the vortex generator 2, can be bent and deformed; when the incoming flow is unstable, under the washing of the fluid, the tail of the vortex generator 2 vibrates under the action of the impact force of the fluid and the elasticity of the fluid, the instability of the fluid above the solid wall surface 1 is increased by the vibration of the vortex generator 2, the strength of the secondary flow is increased, and the convection heat exchange of the solid wall surface 1 is promoted.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An unsteady incoming flow delta wing vortex generator comprises a solid wall surface (1) and a vortex generator (2), and is characterized in that the vortex generator (2) is triangular and is vertically arranged on the solid wall surface (1), an included angle theta between the bottom side of the vortex generator (2) and the incoming flow direction is 30-70 degrees, the vortex generator (2) is made of elastic materials, and a notch (201) is arranged at the tail of the vortex generator (2), so that the tail of the vortex generator (2) can swing within a certain angle, and when an incoming flow exists, the vortex generator (2) can vibrate;

the vortex generator is characterized by further comprising a variable flow rate mechanism (6) arranged on the solid wall surface (1), wherein the variable flow rate mechanism (6) comprises a fluid channel (3) and a turnover sheet which is arranged in the channel and can be turned over, the vortex generator (2) is located behind the fluid channel (3), and when incoming flow exists, the turnover sheet can be turned over and can periodically supply the back to the vortex generator (2) to flow.

2. The delta-wing vortex generator of claim 1, wherein: the fluid channel (3) is in a circular tube shape, two small holes are symmetrically formed in the wall of the circular tube, the turnover piece is composed of a wafer (4) and a turnover shaft (5) penetrating through the circle center of the wafer (4), two ends of the turnover shaft (5) penetrate through the small holes and can rotate in the small holes to drive the wafer (4) to rotate, and the diameter of the part, located outside the fluid channel (3), of the turnover shaft (5) is larger than that of the small holes.

3. The delta-wing vortex generator of claim 2, wherein: the wafer (4) and the overturning shaft (5) are integrally formed.

4. The delta-wing vortex generator of claim 1, wherein: the notch (201) is located at the bottom end of the tail of the vortex generator (2), the height of the notch (201) is 0.2-0.4 times of the height of the vortex generator (2), and the length of the notch (201) is 0.4-0.6 times of the length of the bottom edge of the vortex generator (2).

5. The delta-wing vortex generator of claim 1, wherein: the thickness of the vortex generator (2) is 0.01-0.05 mm.

6. The delta-wing vortex generator of claim 1, wherein: the vortex generators (2) are arranged along the flowing direction of the incoming flow, and the arrangement mode of the vortex generators (2) is in a row or a fork row.

7. The delta-wing vortex generator of claim 1, wherein: the vortex generator (2) is made of aluminum or copper.