AKTU Fluid Mechanics and Fluid Machines · Important Questions 2026Source: ryzenstudy.com PYQs
BME302 Fluid Mechanics and Fluid Machines Important Questions 2026 (AKTU)
Repeat analysis + most-asked questions, unit-wise
What we did: built from all 4 AKTU Fluid Mechanics and Fluid Machines papers (2021-22–2025-26): 98 questions grouped into 63 distinct questions, 21 of which were asked in more than one paper.
- of marks were repeat questions
- 51%
- of marks were repeat questions
- questions asked in 2+ papers
- 21
- questions asked in 2+ papers
- papers analysed (2021-22–2025-26)
- 4
- papers analysed (2021-22–2025-26)
- units, mapped to current syllabus
- 5
- units, mapped to current syllabus
How much of the paper repeats?
- Repeats are real: when we checked each newer BME302 paper against the papers before it, on average 51% of its marks were questions already asked in an earlier paper.
- 2023-24 paper: 46% of marks were repeats (10 of 11 repeated questions were in our top list).
- 2025-26 paper: 56% of marks were repeats (6 of 13 repeated questions were in our top list).
- Topic weightage is a guide, not a guarantee: our Tier 1 + Tier 2 topics covered 61% of the next paper's marks — picking the same number of topics at random would have covered about 58%.
Across 10 subjects and 23 papers we tested, 43% of marks repeated earlier questions on average.
1.Unit-wise most-asked questions
Ranked by how many papers asked them, then by how recently. Click a paper to open it.
Unit 1:
20% of past marks| Question | Asked |
|---|---|
| Discuss the effect of temperature on viscosity of (i) liquids and (ii) gases. | Asked 4× |
| Extend the following: (i) Newton’s law of viscosity (ii) Absolute Pressure, Gauge Pressure and Vacuum Pressure. | Asked 2× |
| The inlet and throat diameters of a horizontal venturimeter are 30 cm and 10 cm respectively. The liquid flowing through the meter is water. The pressure intensity at inlet is 13.734 N/cm² while the vacuum pressure head at the throat is 37 cm of mercury. Find: (i) the rate of flow (ii) value of Cd for the venturimeter. Assume that 4% of the differential head is lost between inlet and throat. | Asked 2× |
| What is the use of venturimeter? Also derive the expression of discharge through venturimeter. | Asked 2× |
Unit 2:
22% of past marks| Question | Asked |
|---|---|
| Derive the continuity equation in Cartesian coordinates, for steady flow of an incompressible fluid. | Asked 3× |
| What is the expression of Reynold number? | Asked 3× |
| The stream function for a two dimensional flow is given by ψ = 2xy. Find: (i) velocity at point P(2,3) (ii) Velocity Potential Function Φ. | Asked 2× |
| Differentiate between rotational and irrotational flows. | Asked 2× |
Unit 3:
19% of past marks| Question | Asked |
|---|---|
| With suitable diagram, illustrate the effect of pressure gradient on Boundary Layer Separation. Identify the conditions for separated and unseparated flow. | Asked 3× |
| A fluid of viscosity 0.7 Ns/m² and specific gravity 1.3 is flowing through a circular pipe of diameter 100 mm. The maximum shear stress at the pipe wall is given as 196.2 N/m², find: (i) pressure gradient (ii) average velocity. 7 marks2025-26 Q6(b) | Asked 1× |
| Outline the following: (i) Frictional loss in pipe flow (ii) Prandtl Mixing Length theory for turbulent shear stress. 7 marks2025-26 Q5(a) | Asked 1× |
| Prandtl Mixing Length theory for turbulent shear stress. 7 marks2025-26 Q5(g) | Asked 1× |
Unit 4:
18% of past marks| Question | Asked |
|---|---|
| Illustrate the velocity triangles for Pelton wheel and derive the expressions for work done by water striking on runner, and maximum hydraulic efficiency of Pelton wheel. | Asked 3× |
| Explain the governing of Pelton Turbine with neat sketch. | Asked 2× |
| Distinguish between Impulse and Reaction turbines. | Asked 2× |
| A reaction turbine works at 450 r.p.m. under a head of 120 m. Its diameter at inlet is 1.2 m and the flow area is 0.4 m². The angles made by absolute and relative velocities at inlet are 20° and 60° respectively with the tangential velocities. Determine: (i) The volume flow rate (ii) The power developed. | Asked 2× |
Unit 5:
21% of past marks| Question | Asked |
|---|---|
| Explain the phenomenon of cavitation. Discuss the effects of cavitation in centrifugal pumps, also outline some precautions against cavitation. | Asked 3× |
| What is slip in case of reciprocating pump? | Asked 3× |
| Derive the expression of minimum speed for starting a centrifugal pump. | Asked 2× |
| Explain and define ideal indicator diagram. Discuss the effect of acceleration in suction and delivery pipe on indicator diagram of reciprocating pump. | Asked 2× |
2.Topic weightage: which topics carry the marks
Blue = Tier 1 + Tier 2 (topics that carried ~80% of past marks). Grey = the rest. It shows where marks have gone, not a promise of what comes next.
Viscosity and temperature · U1
8.3% (cum 8%)
Continuity equation · U2
7.8% (cum 16%)
Pitot, orifice, venturi meters · U1
6.1% (cum 22%)
Streamlines, stream function · U2
5.2% (cum 27%)
Pelton wheel · U4
4.4% (cum 32%)
Separation and control · U3
4.1% (cum 36%)
Indicator diagram · U5
4% (cum 40%)
Specific speed, similar pumps · U5
4% (cum 44%)
Laminar flow in pipes · U3
3.6% (cum 48%)
Jet on fixed, moving surface · U4
3.6% (cum 51%)
Work done, efficiencies · U5
3.4% (cum 55%)
Pipe losses, series, parallel · U3
3.1% (cum 58%)
Boundary layer on flat plate · U3
3% (cum 61%)
Reciprocating pump, slip · U5
3% (cum 64%)
Turbine classification, parts · U4
2.9% (cum 67%)
Surface tension, capillarity · U1
2.9% (cum 69%)
Laminar, turbulent, Reynolds number · U2
2.9% (cum 72%)
Cavitation · U5
2.9% (cum 75%)
Governing of Pelton wheel · U4
2.7% (cum 78%)
Rotational and irrotational flow · U2
2.5% (cum 80%)
Francis, Kaplan turbines · U4
2.5% (cum 83%)
Turbine unit quantities, specific speed · U4
2.3% (cum 85%)
Turbulent layer, laminar sublayer · U3
2.2% (cum 87%)
Types of flow · U2
2% (cum 89%)
Density, gravity, compressibility · U1
1.9% (cum 91%)
Siphon, water hammer · U3
1.8% (cum 93%)
Air vessels · U5
1.5% (cum 95%)
Drag and lift · U3
1.3% (cum 96%)
Pump comparison · U5
1.2% (cum 97%)
Froude number, critical flow · U2
1.2% (cum 98%)
Centrifugal pump classification · U5
1.2% (cum 100%)
Fluid and ideal fluid · U1
0.5% (cum 100%)
| Topic | Papers | Share |
|---|---|---|
| Viscosity and temperature · Unit 1 · Tier 1 | 4/4 | 8.3% |
| Continuity equation · Unit 2 · Tier 1 | 3/4 | 7.8% |
| Pitot, orifice, venturi meters · Unit 1 · Tier 1 | 4/4 | 6.1% |
| Streamlines, stream function · Unit 2 · Tier 1 | 3/4 | 5.2% |
| Pelton wheel · Unit 4 · Tier 1 | 3/4 | 4.4% |
| Separation and control · Unit 3 · Tier 1 | 3/4 | 4.1% |
| Indicator diagram · Unit 5 · Tier 1 | 3/4 | 4% |
| Specific speed, similar pumps · Unit 5 · Tier 1 | 3/4 | 4% |
| Laminar flow in pipes · Unit 3 · Tier 1 | 3/4 | 3.6% |
| Jet on fixed, moving surface · Unit 4 · Tier 1 | 2/4 | 3.6% |
| Work done, efficiencies · Unit 5 · Tier 2 | 3/4 | 3.4% |
| Pipe losses, series, parallel · Unit 3 · Tier 2 | 2/4 | 3.1% |
| Boundary layer on flat plate · Unit 3 · Tier 2 | 2/4 | 3% |
| Reciprocating pump, slip · Unit 5 · Tier 2 | 3/4 | 3% |
| Turbine classification, parts · Unit 4 · Tier 2 | 3/4 | 2.9% |
| Surface tension, capillarity · Unit 1 · Tier 2 | 3/4 | 2.9% |
| Laminar, turbulent, Reynolds number · Unit 2 · Tier 2 | 3/4 | 2.9% |
| Cavitation · Unit 5 · Tier 2 | 3/4 | 2.9% |
| Governing of Pelton wheel · Unit 4 · Tier 2 | 2/4 | 2.7% |
| Rotational and irrotational flow · Unit 2 · Tier 2 | 2/4 | 2.5% |
| Francis, Kaplan turbines · Unit 4 · Tier 3 | 2/4 | 2.5% |
| Turbine unit quantities, specific speed · Unit 4 · Tier 3 | 2/4 | 2.3% |
| Turbulent layer, laminar sublayer · Unit 3 · Tier 3 | 2/4 | 2.2% |
| Types of flow · Unit 2 · Tier 3 | 1/4 | 2% |
| Density, gravity, compressibility · Unit 1 · Tier 3 | 3/4 | 1.9% |
| Siphon, water hammer · Unit 3 · Tier 3 | 2/4 | 1.8% |
| Air vessels · Unit 5 · Tier 3 | 1/4 | 1.5% |
| Drag and lift · Unit 3 · Tier 3 | 1/4 | 1.3% |
| Pump comparison · Unit 5 · Tier 3 | 1/4 | 1.2% |
| Froude number, critical flow · Unit 2 · Tier 3 | 2/4 | 1.2% |
| Centrifugal pump classification · Unit 5 · Tier 3 | 2/4 | 1.2% |
| Fluid and ideal fluid · Unit 1 · Tier 3 | 1/4 | 0.5% |
3.Paper pattern (2025-26)
| Section | Questions | Rule |
|---|---|---|
| A | 7 × 2 marks | Attempt all |
| B | 5 × 7 marks | Attempt any 3 |
| C | 12 × 7 marks | Attempt any 1 |
4.In the syllabus, never asked yet
Low priority, but read them once — a new paper can always start here.
- Bernoulli's equation · U1
- 1D, 2D, 3D flows · U2
- Momentum equation, laminar layer · U3
5.Study order
- 1Viscosity and temperature (Unit 1, Tier 1)
- 2Continuity equation (Unit 2, Tier 1)
- 3Pitot, orifice, venturi meters (Unit 1, Tier 1)
- 4Streamlines, stream function (Unit 2, Tier 1)
- 5Pelton wheel (Unit 4, Tier 1)
- 6Separation and control (Unit 3, Tier 1)
- 7Indicator diagram (Unit 5, Tier 1)
- 8Specific speed, similar pumps (Unit 5, Tier 1)
- 9Laminar flow in pipes (Unit 3, Tier 1)
- 10Jet on fixed, moving surface (Unit 4, Tier 1)
- 11Work done, efficiencies (Unit 5, Tier 2)
- 12Pipe losses, series, parallel (Unit 3, Tier 2)
- 13Boundary layer on flat plate (Unit 3, Tier 2)
- 14Reciprocating pump, slip (Unit 5, Tier 2)
- 15Turbine classification, parts (Unit 4, Tier 2)
- 16Surface tension, capillarity (Unit 1, Tier 2)
- 17Laminar, turbulent, Reynolds number (Unit 2, Tier 2)
- 18Cavitation (Unit 5, Tier 2)
- 19Governing of Pelton wheel (Unit 4, Tier 2)
- 20Rotational and irrotational flow (Unit 2, Tier 2)
FAQ
Which units of BME302 carry the most marks?
Unit 2 (, 22% of past marks) and Unit 5 (, 21% of past marks).
Do AKTU Fluid Mechanics and Fluid Machines questions repeat?
Yes. On average 51% of the marks in each newer BME302 paper came from questions already asked in an earlier paper, and 21 questions have appeared in more than one paper.
How is this list made?
Every question from the 4 papers (2021-22–2025-26) was mapped to the current AKTU syllabus and grouped with the same question from other years. Questions are ranked by how many papers they appeared in, then by how recently.
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Note: this is based on past AKTU papers, not a guarantee. Questions are mapped to the current syllabus; topics that are no longer in the syllabus are left out.