Recent questions tagged applications

The INCORRECT statement about regeneration in vapor power cycle is thatit increases the irreversibility by adding the liquid with higher energy content to the steam gener...

Consider two hydraulic turbines having identical specific speed and effective head at the inlet. If the speed ratio $\displaystyle{\left(\frac{N_1}{N_2}\right)}$ of the t...

The torque (in $N$-$m$) exerted on the crank shaft of a two stroke engine can be described as $T = 10000 + 1000 \sin(2θ) − 1200 \cos(2θ)$, where $θ$ is the crank angle as...

Which of the following statements are TRUE, when the cavitation parameter $\sigma =0$?the local pressure is reduced to vapor pressurecavitation startsboiling of liquid st...

A bullet spins as the shot is fired from a gun. For this purpose, two helical slots as shown in the figure are cut in the barrel. Projections $A$ and $B$ on the bullet en...

Air in a room is at $35^\circ C$ and $60 \%$ relative humidity (RH). The pressure in the room is $0.1 \: MPa$. The saturation pressure of water at $35^ \circ C$ is $5.63...

Steam enters a turbine at $30$ bar, $300^\circ C \: (u = 2750 \: kJ/kg$, $h = 2993 \: kJ/kg)$ and exits the turbine as saturated liquid at $15 \: kPa \: (u = 225 \: kJ/kg...

Refrigerant vapor enters into the compressor of a standard vapor compression cycle at −$10^\circ C \:(h = 402 \: kJ/kg)$ and leaves the compressor at $50^\circ C \: (h = ...

An air-standard Diesel cycle consists of the following processes:$1 – 2$: Air is compressed isentropically.$2 – 3$: Heat is added at constant pressure.$3 – 4$: Air expand...

A resistance-capacitance relaxation circuit is used in an electrical discharge machining process. The discharge voltage is $100$ $V$. At a spark cycle time of $25$ $μs$, ...

In a Rankine cycle, the enthalpies at turbine entry and outlet are $3159$ $kJ/kg$ and $2187$ $kJ/kg$, respectively. If the specific pump work is $2$ $kJ/kg$, the specific...

One kg of air ($R=287 \: J/kg – K$) undergoes an irreversible process between equilibrium state $1(20^{\circ}C$, $0.9 \: m^3$) and equilibrium state $2 ( 20^{\circ} C$, $...

The total emissive power of a surface is $500 \: W/ m^2$ at a temperature $T_1$ and $1200 \: W/m^2$ at a temperature $T_2$, where the temperatures are in Kelvin. Assuming...

The Van der Waals equation of state is $(p+\dfrac{a}{v^2})(v-b)=RT$ where $p$ is pressure, $v$ is specific volume, $T$ is temperature and $R$ is characteristic gas const...

The COP of a Carnot heat pump operating between $6^{\circ}C$ and $37^{\circ}C$ is ___________

In the laminar flow of air ($P_r$ = $0.7$) over a heated plate, if $\delta$ and $\delta _T$ denote, respectively, the hydrodynamic and thermal boundary layer thicknesses,...

Steam enters a well insulated turbine and expands isentropically throughout. At an intermediate pressure, $20$ percent of the mass is extracted for process heating and th...

A well insulated rigid container of volume $1 \: m^3$ contains $1.0 \: kg$ of an ideal gas $[C_p = 1000 \: J/(kg\cdot K)$ and $C_v=800 J/(kg \cdot K)]$ at a pressure of ...

A Carnot engine ($CE_1$) works between two temperature reservoirs $A$ and $B$, where $T_A$ = $900$ $K$ and $T_B$ = $500$ $K$. A second Carnot engine ($CE_2$) works betwee...

A stream of moist air (mass flow rate $= 10.1 \: kg/s$) with humidity ratio of $0.01 \: \dfrac{kg}{\text{kg dry air}}$ mixes with a second stream of superheated water va...

Air enters a diesel engine with a density of $1.0$ $kg$/$m^3$. The compression ratio is $21$. At steady state, the air intake is $30 × 10^{-3}$ $kg/s$ and the net work ou...

In a compression ignition engine, the inlet air pressure is $1$ bar and the pressure at the end of isentropic compression is $32.42$ bar. The expansion ratio is $8$. Assu...

Steam with specific enthalpy $(h)$ $3214$ $kJ/kg$ enters an adiabatic turbine operating at steady state with a flow rate $10$ $kg/s$. As it expands, at a point where h is...

Kaplan water turbine is commonly used when the flow through its runner isaxial and the head available is more than $100$ $m$axial and the head available is less than $10$...

A reversed Carnot cycle refrigerator maintains a temperature of −$5^{\circ}$ $C$. The ambient air temperature is $35^{\circ}$ $C$. The heat gained by the refrigerator at ...

As the temperature increases, the thermal conductivity of a gas increasesdecreasesremains constantincreases up to a certain temperature and then decreases

A diesel engine has a compression ratio of $17$ and cut-off takes place at $10\%$ of the stroke.Assuming ratio of specific heats $(\gamma)$ as $1.4$, the air-standard eff...

At the inlet of an axial impulse turbine rotor, the blade linear speed is $25 \: m/s$, the magnitude of absolute velocity is $100 \: m/s$ and the angle between them is $2...

A certain amount of an ideal gas is initially at a pressure $p_1$ and temperature $T_1$. First, it undergoes a constant pressure process $1$-$2$ such that $T_2$ = $3T_1$/...

Which one of the following pairs of equations describes an irreversible heat engine?$\oint \delta Q 0$ and $\oint \dfrac{\delta Q}{T} < 0 \\$$\oint \delta Q< 0$ and $\oin...