Please use this type of the spread sheet for this question Design of the Bearing (I can't upload the excell sheet for that.)

1. A horizontally-mounted, steam turbine in a power station has a shaft diameter of 600mm and generates an axial thrust of 0.25 MN when operating at 1,500 rpm. The thrust is negligible at zero speed. Misalignment of the shaft is negligible. The runner has a roughness of 0.5 m R_a. Oil supply temp is 50^OC.

1. (a)Design a uni-directional, directed-lubrication, full-complement, tilting-pad thrust bearing according to the design criteria in ESDU 83004 (using the ESDU spread sheet or manually). The lubricant is an ISO 68 oil. The inside diameter of the pads is initially fixed at 0.8m. Place the final design variables, to 3 significant figures, in the row for Design 1 in the table provided overleaf.

1. (b)Demonstrate, below the table, that this your chosen design passes all the required criteria in the design guide.

1. (c)Using the same lubricant, determine the power loss if the inside diameter is 750 mm, 700 mm and 660 mm (for the same actual mean pad pressure you have employed in part (a) the outer diameter can be varied). Enter these in the table as Designs 2, 3 and 4 to 3 significant figures where appropriate. Produce a clearly-labelled graph that shows how the power loss varies with pad inside diameter and explain the significance of this curve for the design of energy-efficient bearings, linking your commentary to the equation for power loss in the Guide.
2. (d)How can the power-loss in part (c) be reduced further using the same lubricant? Enter the data in the table as Design 5.
3. (e)Refine the design (full-complement only) to achieve the lowest power loss you can achieve without exceeding the mean pressure constraint described in (a). You are free to change the all the bearings dimensions and lubricant (ISO VG 22, 32, 46 and 68 oils are available), but you cannot change the load, speed, shaft diameter or surface roughness. Insert any of the results of your study, to 3 significant figures, into the remaining rows of the table to demonstrate that your final design does consume the minimum amount of power. Clearly explain why the power loss is a minimum, relating your answer to the equation for power loss in the ESDU guide (f)Using the data calculated in part (a), estimate the minimum film thickness that would exist if the pad had no side leakage, and the effective viscosity is as calculated in part (a). Why the difference?

In all parts above, you should not exceed the maximum number of pads allowed in the ESDU 83004 design guide, nor exceed the 2MPa actual, maximum mean pressure for white-metal bearings.

Design no.

Oil

(VG)

ACTUAL mean running pressure

(MPa)

Pad inside dia

(mm)

Pad width

(mm)

Pad OUTside dia

(mm)

No of pads

Min. allowable film thickness

(m)

Min. actual film thickness

(m)

Max. allowable roughness of runner

Ra (m)

Max. pad temp

^OC

Total power

Loss

(kW)

1

2

3

4

5

6

7

8

9

10

11

12