CFD Analysis of IV Smart - 50 Hz 2280 CMH Impulse Fan

Transcription

1 Report Project Designation CFD Analysis of IV Smart - 50 Hz 2280 CMH Impulse Fan Client M/s Systemair GmbH, Germany Project Number PR-CFD-019A-15/16-Rev 0 Date of Submission 26/May/2015 Number of pages 11 Mechartes Researchers Pvt. Ltd. D-57, Sector-6, Noida, UP , India Phone: contact@mechartes.com

2 CFD Analysis of IV Smart - 50 Hz 2280 CMH Impulse Fan Introduction Computational fluid dynamics (CFD) can simultaneously predict airflow, heat transfer and contaminant transport in and around buildings. A CFD model is built upon fundamental physical equations of fluid flow and energy transfer. The technique is capable of providing time dependent and as well as steady state solutions to the coupled differential equations that govern fluid flows. Objective The objective of the present work is to estimate the throw length & air volume of the different Systemair ranges of car park impulse fans. Here in this CFD analysis we have carried out the simulation for IV Smart - 50 Hz Impulse fan. Simulation was done according to the following inputs: Table 1 Parameter Formula Used Value Length of the Garage (L) Input by client 100 m Width of the Garage (W) Input by client 20 m Height of the Garage (H) Input by client 3 m Total Volume to be concerned (V) L X W X H 6000 m 3 Ambient Temperatures inside the Garage (T) Input by client 20 O C Position of the Impulse fan in X -direction: Inlet center of fan is 5 meters inside the garage Position of the Impulse fan in Y -direction: Center of the garage or 10meters from the any side wall of the garage Position of the Impulse fan in Z -direction: Below the ceiling. Page 2 of 11

3 Table 2 Impulse Fan Specifications & Boundary Conditions Parameter Value Impulse Fan Used for Simulation IV Smart -50 Hz Model Area of the Impulse Fan at exit 0.703m x 0.067m = m 2 Volume flow rate of impulse fan 2280 CMH Velocity of the impulse fan at outlet of the impulse fan m/sec Inlet opening area of the garage 20 X 3 = 60 m 2 Outlet opening area of the garage 20 X 3 = 60 m 2 Natural Outlet opening (Red Object) Natural inlet opening (Green Object) Fig. 1: Position of Natural Outlet, Natural Inlet in Isometric view (Red shows Natural Outlet opening & Green shows Natural Inlet opening ) Page 3 of 11

4 Inlet Impulse Fan Outlet Fig. 2: Position of Natural Outlet, Natural Inlet in Top view Fig. 3: Position of Natural Outlet, Natural Inlet in Side view Page 4 of 11

5 CFD Simulation Results: (1) Following figures shows the contours of Impulse Fan Velocities in different planes Fig. 4(a): Contour plot of Velocity magnitude at Impulse Fan Height from Ground of Garage in Horizontal Plane Fig. 4(b): Contour plot of Velocity magnitude at center of the Garage in vertical Plane Page 5 of 11

6 Fig. 4(c): Contour plot of Velocity magnitude at 2 meter Height from Ground of Garage in Horizontal Plane Fig. 4(d): Contour plot of Velocity magnitude at 1.5 meter Height from Ground of Garage in Horizontal Plane Page 6 of 11

7 Fig. 4(e): Contour plot of Velocity magnitude at 1 meter Height from Ground of Garage in Horizontal Plane Fig. 4(f): Contour plot of Velocity magnitude in different vertical planes of Garage (it can be seen that after 40 meters of length from the impulse fan, velocities are decreased) Page 7 of 11

8 All the blue color in above image is negative X-velocities Fig. 4(g): Contour plot of Positive X-directional velocities in different vertical planes of Garage Fig. 4(h): Velocity path lines at Impulse Fan Height from Ground of Garage in Horizontal Plane Page 8 of 11

9 (2) Following figures shows Impulse Fan Velocities with minimum terminal velocity of 1 m/sec Fig. 5(a): Contour plot of Velocity magnitude in isometric view of Garage Fig. 5(b): Contour plot of Velocity magnitude in top view of Garage at impulse fan height Page 9 of 11

10 Fig. 5(c): Contour plot of Velocity magnitude in side view of Garage Conclusion: In above 3 images the minimum velocity taken as 1 m/sec, velocities below 1 m/sec are not shown in the above images. From above 3 images we can clearly see that the throw length of the Impulse Fan is about 35.5 meters. (3) Following figure shows the Air Velocities planes with terminal velocity 1 m/sec & 0.5 m/sec Fig. 6(a): Contour plot of Velocity with terminal velocity 1 m/sec, i.e. plane at 35.5m throw length along x - direction Page 10 of 11

11 Fig. 6(b): Contour plot of Velocity with terminal velocity 0.5 m/sec, i.e. plane at 44.4m throw length along x - direction Table 3 Parameter Formula Used Result Average air velocity at 35.5m throw length (V 35.5m ) Area of the positive velocity clip at 35.5m throw length (A 35.5m ) Induced Airflow at 35.5 m throw length (with 1 m/sec terminal velocity) From CFD, refer to Figure 6(a) m/sec From CFD, refer to Figure 6(a) m 2 I 35.5m = (V 35.5m ) X (A 35.5m ) CMH Induction Factor = I 35.5m /2280 cmh Average air velocity at 44.4m throw length (V 44.4m ) Area of the positive velocity clip at 44.4m throw length (A 44.4m ) Induced Airflow at 44.4 m throw length (with 0.5 m/sec terminal velocity) From CFD, refer to Figure 6(b) m/sec From CFD, refer to Figure 6(b) m 2 I 44.4m = (V 44.4m ) X (A 44.4m ) CMH Induction Factor = I 44.4m /2280 cmh Note: In above induced air flow calculations, only the positive velocity vectors area were considered. Conclusions: From above CFD results we can conclude that the length of the throw of the IV Smart - 50Hz impulse fan is 35.5 meters with a terminal velocity of 1 m/sec; this fan can push the air at the length of 35.5meters. And the induced airflow at the end of 35.5 meter throw length is CMH. Page 11 of 11