Recent content by Sara1

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    Thermodynamics; Pressure and Temperature at the Nozzle inlet

    Isentropic Efficiency= Measures the deviation of actual processes from the corresponding isentropic ones. Thus, for a nozzle: 0.83= Actual Kinetic Energy at Nozzle Exit/ Isentropic KE at Nozzle Exit
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    Thermodynamics; Pressure and Temperature at the Nozzle inlet

    Homework Statement CO2 gas enters a nozzle with an isentropic efficiency of 83% with a low velocity. It exits the nozzle at 110 kpa and 59K and 246m/s. Determine the pressure at the nozzle inlet assuming: Homework Equations -Constant specific heats at room temperature -Variable specific...
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    Thermodynamics; Finding Work of a Piston cylinder Device

    I figured out how to solve it as well. Since the process is reversible, then the piston is adiabatic, then the process is isentropic. Thus, s1=s2. We can Find the work using the equation -W=m(U2-U1) The u1 is determined from state one from the given information. To find U2, we must realize that...
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    Thermodynamics; Finding Work of a Piston cylinder Device

    Oh, so shall i use the equation Q=m*cv*(T2-T1) instead? The t1 is given and i can find the t2 from the pressure=900kpa
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    Thermodynamics; Finding Work of a Piston cylinder Device

    why will the volume be equal to zero?
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    Thermodynamics; Finding Work of a Piston cylinder Device

    How do i use the latent heat to find the work? Do i calculate to find the h or perhaps find the specific volume then multiply by the mass to find the volume. then i can use the equation of work which is: w=p(v2-v1)
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    260 liter rigid tank contains saturated-liquid water at 185oC

    Homework Statement A 260 liter rigid tank contains saturated-liquid water at 185oC. A valve at the bottom of the tank is opened and water is allowed to escape from the tank. The valve remains opened until all of the water inside of the tank is vaporized completely. During this process, heat...
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    Thermodynamics; Finding Work of a Piston cylinder Device

    Homework Statement An insulated piston-cylinder device contains 5 kg of water at 100oC with a quarter of the mass is vapor. The water is compressed reversibly to 900 kPa. Find the work done during this process. Let the ambient temperature to be 27oC. Homework Equations I can use the...
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    Thermodynamics: Vapor Compression Refrigeration that is Adiabatic?

    Consider a heat pump works on the vapor-compression refrigeration cycle with 0.2 kg/s of refrigerant-134a as the working fluid. The cycle is used to maintain a house at 26oC while absorbing heat from the outdoors at 3oC. R-134a enters the compressor at 200 kPa as a saturated vapor and leaves at...
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    Thermodynamics: Vapor-compression refrigeration

    The refrigerator at a house is driven by a vapor-compression refrigeration cycle shown in figure 6-19 in the textbook. Assume the refrigeration cycle is used to keep the interior of the refrigerator at -5oC at all times. When the kitchen’s temperature is 32oC, the refrigerator is estimated to be...
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