📝 [PIPE] QB ID: 1508131424010823 | Essential & Supplementary Problems | Set 03

A rectangular foundation cross -section has a bed plate dimension of 8 ft x 10 ft. The uniform clearance on each side is 1 ft. The height of the foundation is 4.5 ft. If the weight of the steel bar reinforcements needed is ½% of weight of foundation, find t he weight of the steel bars. Use concrete density of 2400 kg/m³.

A steam pipe having a surface temperature of 250°C passes through a room where the temperature is 27°C. The outside diameter of the pipe is 100 mm and emissivity factor is 0.8. Calculate the radiated heat loss for 3 m pipe length.

Brine enters a circulating brine cooler at the rate of 60 m³/hr at -8°C and leaves at -18°C. Specific heat of brine is 1.072 kJ/kg-K and a specific gravity of 1.12. Determine the tons of refrigeration.

A turbo-charged, 16 cylinder, Vee-type diesel engine has an air consumption of 3,000 kg/hr per cylinder at rated load and speed. This air is drawn in through a filter by a centrifugal compressor directly connected to the exhaust gas turbine. The temperature of the air from thecompressor is 135°C and a counter flow air cooler reduces the air temperature to 45 °C before it goes to the engine suction header. Cooling water enters the air cooler at 30°C and leaves at 40°C. Calculate the log mean temperature difference.

Water is flowing in a pipe with radius of 30 cm at a velocity of 5 m/s at the temperature in the pipe. The density and viscosity of the water are as follows: density = 997.9 kg/s viscosity = 1.131 Pa-s. What is the Reynolds number for this situation?

Compute the amount of condensate formed during a 10 minute warm-up of 180 meter pipe conveys the saturated steam with enthalpy of vaporization, hfg = 1947.8 kJ/kg. The minimum external temperature of pipe is 2°C. The final temperature of pipe is 195°C. The specific heat of pipe material is 0.6 kJ/kg-°C. The specific weight is 28 kg/m.

The discharge pressure of an air compressor is 5 times the suction pressure. If volume flow at suction is 0.1 m³/s, what is the suction pressure if compressor work is 19.57 kW (use n = 1.35).

The initial condition of air in an air compressor is 98 kPa and 27 °C and discharges air at 450 kPa. The bore and stroke are 355 mm and 381 mm, respectively with percent clearance of 8% running at 300 rpm. Find the volume of air at suction.

An air compressor has a suction volume of 0.35 m³/s at 97 kPa and discharges at 650 kPa. How much power is saved by the compressor if there are two stages?

A two stage air intercooler has an intercooler pressure of 4 kg/cm². What is the discharge pressure if suction pressure is 1 kg/cm²?

A two-stage air compressor at 100 kPa and 22°C discharges to 750 kPa. If the intercooler intake is 105°C, determine the value of n.

A single acting compressor has a volumetric efficiency of 89%, operates at 500 rpm. It takes in air at 100 kPa and 30°C and discharges it at 600 kPa. The air handled is 8 m³/min measured at discharged condition. If compression is isentropic, find the effective mean pressure in kPa.

A water-jacketed air compressor handles 0.343 m³/s of air entering at 96.5 kPa and 21°C and leaving at 480 kPa and 132°C; 10.9 kg/hr of cooling water enters the jacket at 15°C and leaves at 21°C. Determine the compressor brake power.

A double suction centrifugal pump delivers 20 ft³/s of water at a head of 12 m and running at 650 rpm. What is the specific speed of the pump?

Determine the number of stages needed for a centrifugal pump if it is used to deliver 400 gal/min of water and pump power of 15 hp. Each impeller develops a head of 30 ft.

The suction pressure of a pump reads 3 in. of mercury vacuum and discharge pressure reads 140 psi is used to deliver 120 gpm of water with specific volume of 0.0163 ft³/lb. Determine the pump work.

A submersible pump delivers 350 gpm of water to a height of 5 ft from the ground. The pump where installed 150 ft below the ground level and a drawdown of 8 ft. during the operation. If water level is 25 ft above the pump, determine the pump power.

A vacuum pump is used to drain a flooded mine shaft of 20°C water. The pump pressure of water at this temperature is 2.34 kPa. The pump is incapable of lifting the water higher than 16 m. What is the atmospheric pressure?

A submersible, multi-stage, centrifugal deep well pump 260 gpm capacity is installed in a well 27 ft below the static water level and running at 300 0 rpm. Drawdown when pumping at rated capacity is 10 feet. The pump delivers the water into a 25,000 gallons capacity overhead storage tank. Total discharge head developed by pump, including friction in piping is 243 ft. Calculate the diameter of the impel ler of this pump in inches if each impeller diameter developed a head of 38 ft.

A fan draws 1.42 m³ per second of air at a static pressure of 2.54 cm of water through a duct 300 mm diameter and discharges it through a duct of 275 mm diameter. Determine the static fan efficiency if total fan is 75% and air is measured at 25°C and 760 mm Hg.

A water cooler uses 50 lb/hr of melting ice to cool running water from 80°F to 42°F. Based on the inside coil area, U_i = 110 Btu/hr-ft²-°F. Find the gpm of water cooled.

The charge in a Diesel engine consists of 18.34 grams of fuel, with lower heating value of 42,571 kJ/kg, and 409 grams of fuel and products of combustion. At the beginning of compression, T1 = 60°C. Let rk = 14. For constant cp = 1.11 kJ/kg-°C, what should be the cut-off ratio in the corresponding ideal cycle?

The gain of entropy during isothermal nonflow process of 5 lb of air at 60°F is 0.462 Btu/°R. Find the V₁/V₂.

An auditorium seating 1500 people is to be maintained at 80°F dry bulb and 60°F wet bulb temperature when outdoor air is at 91°F dry bulb and 75°F wet bulb. Solar heat load is 110,000 Btu/hr and supply air is at 60°F, determine the amount of supply air.

In a Brayton cycle that operates between temperature limits of 300 K and 1773 K with k = 1.4, determine the temperature at the end of compression (isentropic) for maximum work of the cycle.

A 35% solution leaves the absorber and 30% solution enters the absorber. The heat removed from the absorber by cooling wate r is 547.6 Btu and ammonia is superheated by 10°. Find the pound per pound of ammonia gas from the evaporating coils.

A Carnot refrigeration system operates at T_max/T_min = 1.5. Find the kW per ton of refrigeration.

Assume 8 ft³ of air at 100 psi and 100°F are compressed isothermally to a volume of 2 ft³. For each end state of the process, find the bulk modulus.

Predict the pressure of nitrogen gas at T = 200 K and υ = 0.00385 L/g and b = 0.00141 L/g; a = 0.178 L²-kPa/g². Use Van der Waals equation.

A Francis turbine is to be operated at a speed of 600 rpm and with discharge of 4 m³/s. If r₁ = 0.6 m, β = 110°, and the blade height B is 10 cm, what should be the guide vane angle α₁ for non-separating flow condition at the runner entrance?

The total head of fan is 187 m and has a static pressure of 210 mm of water gage, what is the velocity of air flowing if the density of air is 1.15 kg/m³?

A fan delivers 5.7 m³/s at a static pressure of 5.08 cm of water when operating at a speed of 400 rpm. The power input required is 2.963 kW. If 7.05 m³/s are desired in the same fan and installation, find the pressure in cm of water.

A rigid container is closed at one end and measures 8 in diameter by 12 in long. The container is held vertical and is slowly moved downward until the pressure in the container is 17 psia. What will be the depth of the top of the container from the free water surface?

An empty, open can is 30 cm high with a 15 cm diameter. The can, with the open end down, is pushed under water with a density of 1000 kg/m³. Find the water level in the can when the top of the can is 50 cm below the surface.

A cylindrical pipe with water flowing downward at 0.03 m³/s having top diameter of 0.08, bottom diameter of 0.04 m and height of 1.5 m. Find the pressure inside the pipe.

Determine the size of pipe which will deliver 8 liters of medium oil ( ν = 6.10 x 10^-6 m²/s) assuming laminar flow conditions.

The type of flow occupying in a 1 cm diameter pipe which water flows at a velocity of 2.50 m/s. Use ν = 1.13 x 10^-6 m²/s for water.

What force is exerted by a water jet, 60 mm in diameter, if it strikes a wall at the rate of 15 m/s?

A 300 mm diameter pipe discharges water at a rate of 200 li/s. Point 1 on the pipe has a pressure of 260 kPa and 3.4 m below point 1 is point 2 with a pressure of 300 kPa. Compute the head loss between points 1 and 2.

Water flowing at the rate of 10 m/s from an orifice at bottom of a reservoir. Find the pressure at the bottom of reservoir.

Steam flows through a nozzle at 400°C and 1 MPa (h = 3263.9 kJ/kg) with velocity of 300 m/s. Find the stagnation enthalpy.

Air flows through a nozzle at a speed of 350 m/s. Find the stagnation temperature if the entrance temperature is 200°C.

Carbon dioxide flows through a nozzle with a speed of 400 m/s. Compute the dynamic temperature.

Carbon dioxide flows through a nozzle with speed of 380 m/s. The entrance condition of nozzle is 250°C and 1200 kPa. Find the stagnation pressure.

Air enters a diffuser with a velocity of 200 m/s. Determine the velocity of sound if air temperature is 30°C.

Air flows through a nozzle with temperature of entrance of 420 K stagnation temperature of 468 K. Find the Mach number.

Air at 300 K and 200 kPa is heated at constant pressure to 600 K. Determine the change of internal energy.

An insulated rigid tank initially contains 1.5 lb of helium at 80°F and 50 psia. A paddle wheel with power rating of 0.02 hp is operated within the tank for 30 min. Determine the final temperature.

A 4 m² asphalt pavement with emissivity of 0.85 has a surface temperature of 50°C. Find the maximum rate of radiation that can be emitted from the surface.

Air at 10°C and 80 kPa enters a diffuser of a jet engine steadily with a velocity of 200 m/s. The inlet area of diffuser is 0.40 m². Determine the mass flow rate of air.