Study on Flow Field Characteristics of the 90° Rectangular Elbow in the Exhaust Hood of a Uniform Push–Pull Ventilation Device
Abstract
:1. Introduction
2. Materials and Methods
2.1. Research Condition
2.2. Model Establishment
2.3. Mesh
2.4. Control Equations, Boundary Conditions and Solution Parameters
3. Results
3.1. Influence of Curvature Radius on Wind Trace
3.2. Ventilation Non-Uniformity
- β: uniformity of wind velocity;
- vi: wind velocity at any measurement point;
- : average wind velocity; and
- n: number of measuring points.
3.3. Bend Pressure Loss
4. Discussion
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Boundary Conditions | Definition |
---|---|
Exhaust boundary type | Velocity-inlet |
Inlet velocity magnitude (m/s) | −13 |
Hydraulic diameter (m) | 0.2 |
Turbulence intensity (%) | 3.62 |
Suction boundary type | Pressure outlet |
Hydraulic diameter (m) | 0.84 |
Turbulence intensity (%) | 3.03 |
Solver | Definition |
---|---|
Solver | Segregated |
Viscous model | k-epsilon (k-ε) |
Pressure–velocity coupling | SIMPLEC |
Discretization scheme | Second-order upwind |
Convergence criterion | 10−6 |
Elbow Type | Average Wind Velocity (m/s) | Non-Uniformity (%) |
---|---|---|
R = 0 h | 5.10 | 48.84 |
R = 1 h | 4.96 | 29.67 |
R = 2 h | 4.93 | 22.13 |
R = 2.5 h | 4.88 | 20.65 |
R = 3 h | 4.91 | 18.47 |
R = 4 h | 4.91 | 14.98 |
Elbow Type | Average Wind Pressure (Pa) | Non-Uniformity (%) |
---|---|---|
R = 0 h | −40.92 | 9.69 |
R = 1 h | −34.58 | 8.00 |
R = 2 h | −29.31 | 14.40 |
R = 2.5 h | −28.80 | 12.79 |
R = 3 h | −28.60 | 11.64 |
R = 4 h | −28.59 | 10.24 |
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Wu, X.; Liu, L.; Luo, X.; Chen, J.; Dai, J. Study on Flow Field Characteristics of the 90° Rectangular Elbow in the Exhaust Hood of a Uniform Push–Pull Ventilation Device. Int. J. Environ. Res. Public Health 2018, 15, 2884. https://doi.org/10.3390/ijerph15122884
Wu X, Liu L, Luo X, Chen J, Dai J. Study on Flow Field Characteristics of the 90° Rectangular Elbow in the Exhaust Hood of a Uniform Push–Pull Ventilation Device. International Journal of Environmental Research and Public Health. 2018; 15(12):2884. https://doi.org/10.3390/ijerph15122884
Chicago/Turabian StyleWu, Xiang, Lindong Liu, Xiaowei Luo, Jianwu Chen, and Jingwen Dai. 2018. "Study on Flow Field Characteristics of the 90° Rectangular Elbow in the Exhaust Hood of a Uniform Push–Pull Ventilation Device" International Journal of Environmental Research and Public Health 15, no. 12: 2884. https://doi.org/10.3390/ijerph15122884