Week 12 - Final Project - Modelling and Analysis of a Datacenter

Objective:

To create model of data center which include computer room air conditioning units (CRACs), server cabinets, power distribution units (PDUs), and perforated floor tiles in the datacenter. and study the flow distribution and behavior of server stacks in data center

Problem description:

This tutorial considers a 1200 sq. ft. datacenter with a slab to slab height of 12 ft. The datacenter consists of a 1.5 ft underfloor plenum and a 2 ft ceiling plenum. The CRACs discharge cold air into the underfloor plenum. The cold air enters the main datacenter space mainly through the perforated floor tiles and returns back to the air conditioning units. The cooling load, as summarized as below. Size and Capacity of Heat Sources in Datacenter corresponds to the heat output from the server cabinets and the PDUs. A PCB board, library files and traces are imported to create the model. The model is first solved for conduction only, without the components and then solved using the actual components with forced convection.

Heat Source	Size	Power
Server Cabinet	2 ft x 3 ft x 7 ft	3000 W
High Density	2 ft x 3 ft x 7 ft	7000 W
PDU	4 ft x 2 ft x 5 ft	3600 W

Datacenter:

A data centre is a building or a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems.

Since IT operations are crucial for business continuity, it generally includes redundant or backup components and infrastructure for power supply, data communication connections, environmental controls and various security devices. A large data center is an industrial-scale operation using as much electricity as a small town.

Geometry:

1.Create Geometry of cabinet with given dimensions

2.Pictures of cabinet

3.Create geometry of Raised floor

4.Picture of Raised floor

5.Geometry of CRAC

6.Copy CRAC and translate to get another CRAC2 together form a group CRAC

7.Create racks with heat load of3000W

8.Create copy of racks translate by x=7ft

8.Picture of racks

9. Create HD Racks with heat load 7000W

10. Create Tiles with the geometry

11. Picture of tiles(n=11) is as shown

12.Copy Tiles and Translate in x direction to get another set of Tiles

13 Similarly create Tiles on other side

14. Create grills for flow to be exhausted

15. Create PDU with heat load of 3600W

Meshing:

1. Total Number of elements=141917 and Total number of nodes=167936

2.Do mesh seperately for CRAC and give x,y,z count

3.Cutplane along x-axis

4. Cutplane along y-axis

5. Cutplane along z-axis

Numerical setup:

1.solve for velocity,Pressure,temperature and species

2. Flow has inlet/outlet (Forced convection)

3.Set flow regime as turbulent

4. Turbulent model (Zero equation)

5.ignore heat transfer due to radiation

6.Apply steady state

7.Enable gravity in negative y direction (g=-9.81)

8.Natural convection Ideal gas laws of pressure=101325 N/m2

2.Solution settings

1. set no of iterations 500 and convergence criteria for energy to 1e-12
2. Temperature Linear solver: F cycle is selected for Type Enter 1e-6 for both the Termination criterion and Residual reduction tolerance
3. Select Double for the solver Precision.

Contours:

1. Residuals

2.Monitor points

Temperature contours:

1.From contours it shows that min temp=12.77oC and Max temp=29.7oC

Cutplane contours:

Contours of partices:

1.Flow of particles are shown in fig