Because a large portion of turbine work is eaten away by compressor and its inefficiency will affect net power output and cost of generation.
Posted Date:- 2022-06-25 13:18:36
Ratio of their thickness
(Prandtl number)-1/3.
Posted Date:- 2022-06-25 13:17:40
Cyclone furnace.
Posted Date:- 2022-06-25 13:17:01
Heat pump.
Posted Date:- 2022-06-25 13:16:36
Supercritical boilers do not head heavy drum for separation of steam from mixture of water and steam.
Posted Date:- 2022-06-25 13:16:08
UK, USA and Germany respectively.
Posted Date:- 2022-06-25 13:15:32
Engine to burn lean mixture uses high compression ratio and the highly turbulent movement of the charge is produced by the
geometry of the combustion chamber.
Posted Date:- 2022-06-25 13:15:06
Thermaln is high for weak mixture and it decreases as mixture strength becomes rich.
Posted Date:- 2022-06-25 13:14:41
In two-stroke engine lub oil is mixed with petrol and thus some lub oil is blown out through the exhaust valves by scavenging
and charging air. There is no such wastage in four stroke petrol engine.
Posted Date:- 2022-06-25 13:14:17
Glycerine has boiling point of 90°C which inereases its heat carrying capacity. Thus weight of coolant gets reduced and smaller
riadiator can be used.
Posted Date:- 2022-06-25 13:13:35
Sulphates and chlorides of lime and magnesium form hard scale, and carbonates of lime and magnesium form soft scale.
Posted Date:- 2022-06-25 13:12:45
It is the actual physical change in metal that makes it extremely brittle and filled with minute eracks. It occurs particularly in
the seams of rivetted joints and around the rivet holes.
Posted Date:- 2022-06-25 13:11:23
Non uniform corrosion over the entire metal surface, but occurring only in smalls pits is called pitting. It is caused by lack of
uniformity in metal.
Posted Date:- 2022-06-25 13:10:50
Anergy.
Posted Date:- 2022-06-25 13:10:12
Isentropic efficiency of axial flow compressor is higher.
Posted Date:- 2022-06-25 13:09:39
The maximum power is consumed at about 70% of maximum flow in case'of fan with backward blades. For higher flow, power consumption gets lower.
Posted Date:- 2022-06-25 13:09:16
Stalling is a local phenomenon and it occurs when How breaks away from the blades. Surging causes complete breakdown of flow and as such it affects the whole machine.
Posted Date:- 2022-06-25 13:07:19
It is least when compression process approaches isothermal. For this purpose, attempts are made to cool the air during compression.
Posted Date:- 2022-06-25 13:06:46
At the critical pressure ratio.
Posted Date:- 2022-06-25 13:05:37
COP of heating is one(unity) more than COP of cooling.
Posted Date:- 2022-06-25 13:05:00
Nil
Posted Date:- 2022-06-25 13:04:42
Polished surface promotes drop wise condensation and does not wet the surface.
Posted Date:- 2022-06-25 13:04:28
Temperature.
Posted Date:- 2022-06-25 13:04:09
It satisfies equation of state and its specific heats are constant.
Posted Date:- 2022-06-25 13:03:56
Because there is no heat transfer in this process.
Posted Date:- 2022-06-25 13:03:33
Seavenging is process of flushing out burnt gases from engine cylinder by introducing freslh air in the cylinder before exhaust stroke ends. Supercharging is the process of supplying higher mass of air by compressing the atmospheric air.
Posted Date:- 2022-06-25 13:02:10
Throttling process.
Posted Date:- 2022-06-25 13:01:35
Entropy is extensive property.
Posted Date:- 2022-06-25 13:00:49
Constant volume line. Slope is variable.
Posted Date:- 2022-06-25 13:00:32
Free energy (or Helmholtz function) is defined as/= u -Ts.
It is equal to the work during a constant-volume isothermal reversible nonflow process.
Ts
Free enthalpy (or Gibbs function) is defined asg =h
(where u = internal energy, h= enthalpy, T= temperature, s = entrop)
Gibbs function is of particular importance in processes where chemical changes occur. For reversible isothermal steady-flow
processes or tor reversible constant-pressure isothermal nonflow processes, change in free energy is equal to net work.
Posted Date:- 2022-06-25 12:51:44
For pure substances, the heat effects accompanying changes in state at constant pressure (notemperature change being
evident) are known as latent heats. Examnples of latent heats are : heat of fusion, vaporisation, sublimation, and change in
erystal form.
Posted Date:- 2022-06-25 12:34:06
For aqueous solutions of salts, the specific heat can be estimated by assuming the specific heat of the solution equal to that of
the water alone. Thus, for a 15% by weight solution of sodiunm chloride in water, the specific heat would be approximately o. 85.
Posted Date:- 2022-06-25 12:33:22
• The heat capacity of a material is the amount of heat transformed to raise unit mass of a material 1 degree in temperature.
• The specific heat of a material is the ratio of the amount of heat transferred to raise unit maSs of a material 1 degree in temperature to that required to raise unit mass of water 1 degree of temperature at some specified temperature.
• For most engineering purposes, heat capacities may be assumed numerically equal to;specifie heats.
Posted Date:- 2022-06-25 12:32:55
According to Bauschinger, the limit of proportionality of material does not remain constant but vaies aceording to the direction
of stress under cyclic stresses.
Posted Date:- 2022-06-25 12:32:03
Whiskers are very small crystals which are virtually free from imperfections and dislocations.
Posted Date:- 2022-06-25 12:31:43
Embrittlement attack is usually intergranular in metals, i.e. cracks progress between the grains of the polycrystalline material.
It imparts a tendency to fail under a static load after a given period of time in those alloy steels which are susceptible to
embrittlement.
Posted Date:- 2022-06-25 12:30:43
Isothermal process.
Posted Date:- 2022-06-25 12:30:25
Metallic bond is strongest and molecular bond also known as Vander Waals bond is weakest.
Posted Date:- 2022-06-25 12:29:04
Manganese increases tensile strength and hardness. It decreases weldability.
Posted Date:- 2022-06-25 12:27:40
Efficiency ratio.
Posted Date:- 2022-06-25 12:26:00
Seven factors influencing type of failure are:
1. Type of material (inherent structure properties),
2. Manner of loading (Static versus dynamic),
3. Range of imposed stress,
4. Strain rate (static, dynamic, impact),
5. Stress distribution (discontinuity in material/shape),
6. temperature, and
7. surtace treatment.
Posted Date:- 2022-06-25 12:25:34
Galvanizing consumes the largest proportion of zinc. Zinc is resistant to corrosion but is attacked by acids and alkalies. Zine alloys are suited for making die casting since the melting point is reasonably low.
Posted Date:- 2022-06-25 12:25:12
Magnesium is used to alloy with aluminium and as an additive for making SG (Spheroidal Graphite) iron.
Posted Date:- 2022-06-25 12:24:46
Admirality brass with 296 zinc and 1% tin has good corrosion resistance and is used for condenser and feed heater tubes.
Aluminium is also added to brass to improve corrosion resistance.
Posted Date:- 2022-06-25 12:24:29
By addition of zinc in copper, both tensile strength and elongation increases. The 70/3o brass has excellent deep drawing property and is used for making radiator fins.
Posted Date:- 2022-06-25 12:23:46
Brass is an alloy of copper with zinc; and bronze is alloy of copper with tin.
Posted Date:- 2022-06-25 12:22:52
Sulphides, when attached with dilute acid, evolve hydrogen sulphide gas which stains bromide paper and therefore can be
readily detected in ordinary steels and cast irons. While sulphur is not always as harmful as is sometimes supposed, a sulphur
print is a ready guide to the distribution of segregated impurities in general.
Posted Date:- 2022-06-25 12:22:07