Sommerfeld number is (A) Similar to bearing characteristic number (B) Similar to Reynold’s number (C) Dimensionless parameter that contains all the design parameters (D) Used to find out dynamic load carrying capacity of the hydrodynamic bearing

Sommerfeld number is

(A) Similar to bearing characteristic number

(B) Similar to Reynold’s number

(C) Dimensionless parameter that contains all the design parameters

(D) Used to find out dynamic load carrying capacity of the hydrodynamic bearing
by

1 Answer

Answer :

(C) Dimensionless parameter that contains all the design parameters
by

Related questions

What is the main advantage of hydrodynamic bearing over roller bearing? (a) Easy to assemble [IES-2005] (b) Relatively low price (c) Superior load carrying capacity at higher speeds (d) Less frictional resistance

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The bearing characteristic number in a hydrodynamic bearing depends on- (a) Length, width and load (b) length, width and speed. [IES-1996] (c) Viscosity, speed and load (d) viscosity, speed and bearing pressure.

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Last Answer : (d) viscosity, speed and bearing pressure.

Which one of the following is correct? [IES-2008] A hydrodynamic slider bearing develops load bearing capacity mainly because of- (a) Slider velocity (b) wedge shaped oil film (c) Oil compressibility (d) oil viscosity

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A journal bearing with hydrodynamic lubrication is running steadily with a certain amount of minimum film thickness. When the load and speed are doubled, how does the minimum film thickness vary? [IES-2008] (a) Remains unchanged (b) Gets doubled (c) Gets reduced to one-fourth of original value (d) Gets reduced to half of original value

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Assertion (A): In steady rotating condition the journal inside a hydrodynamic journal bearing remains floating on the oil film. [IES-2008] Reason (R): The hydrodynamic pressure developed in steady rotating conditions in journal bearings balances the load on the journal. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true but R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true

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A journal bearing is a ______ contact bearing working on the hydrodynamic lubrication and which supports load in____ direction. a) Sliding, Axial b) Rolling, Radial c) Sliding, Radial d) Rolling, Axial

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Which one of the following pair is correctly matched? [IES-2000] (a) Beauchamp tower ........................First experiments on journal bearings (b) Osborne Reynolds ........................Antifriction bearings (c) Somerfield number........................Pivot and Collar bearings (d) Ball bearings...............................Hydrodynamic lubrication

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Assertion (A): Hydrostatic lubrication is more advantageous when compared to hydrodynamic lubrication during starting and stopping the journal in its bearing. Reason (R): In hydrodynamic lubrication, the fluid film pressure is generated by the rotation of the journal. [IES-1998] (a) Both A and R are individually true and R is the correct explanation of A (b) Both A and R are individually true but R is not the correct explanation of A (c) A is true but R is false (d) A is false but R is true

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Satisfactory hydrodynamic film in a journal bearing is formed when (a) Journal speed is low; unit pressure on the bearing is high and viscosity of lubricant used is low [IES-2006] (b) Journal speed is low; unit pressure on the bearing is low and viscosity of lubricant used is low (c) Journal speed is high; unit pressure on the bearing is high and viscosity of lubricant used is high (d) Appropriate combination of journal speed, unit pressure on bearing and lubricant viscosity exists resulting in low coefficient of friction

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Increase in values of which of the following results in an increase of the coefficient of friction in a hydrodynamic bearing? [IES 2007] 1. Viscosity of the oil. 2. Clearance between shaft and bearing. 3. Shaft speed. Select the using the code given below: (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

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For elasto-hydrodynamic lubrication (A) There should be relative motion between the surfaces of the journal and the bearing and wedge shaped clearance space (B) There should be external source like pump to supply lubricant under pressure (C) There should be elastic deformation of the parts in contact (D) There should be metal to metal contact

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In hydrodynamic bearing, when the shaft begins to rotate in clockwise direction, (A) The journal climbs to the right side of the bearing without metal to metal contact (B) The journal climbs to the left side of the bearing without metal to metal contact (C) The journal sinks down to the bottom of the bearing (D) The journal is at the center of the bearing

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Boundary lubricated bearing is (A) Thick film bearing (B) Thin film bearing (C) Hydrodynamic bearing (D) Hydrostatic bearing

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If we exclude the cost factor, which bearing is preferred? a) Hydrostatic b) Hydrodynamic c) Both are equally preferred d) Cannot be determined

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In the expression of dynamic load capacity P=XVF r + YF a , X stands for? (a) Race rotation factor (b) Radial load factor (c) Thrust load factor (d) Service factor

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In the expression of dynamic load capacity P=XVF r + YF a , V stands for? (a) Race rotation factor (b) Radial load factor (c) Thrust load factor (d) Service factor

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The type of spring used to achieve greater load carrying capacity within given space is (A) Spiral spring (B) Springs in series (C) Multi-leaf spring (D) Concentric springs

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If μ = absolute viscosity, N= speed of the journal and p = unit bearing pressure, then the bearing characteristic number is given by (A) μN/p (B) μp/N (C) pN/μ (D) μ/pN

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Assertion (A): In hydrodynamic journal bearings, the rotating journal is held in floating condition by the hydrodynamic pressure developed in the lubricant. Reason (R): Lubricant flows in a converging-diverging channel. [IES-1994] (a) Both A and R are individually true and R is the correct explanation of A (b) Both A and R are individually true but R is not the correct explanation of A (c) A is true but R is false (d) A is false but R is true

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