A rocket motor burns LH2 and LOX. The combustion chamber pressure and temperature are 25 atmospheres...

A rocket motor burns LH2 and LOX. The combustion chamber pressure and temperature are 25 atmospheres and 3517 K, respectively. The area of the nozzle throat is 0.1 m^2. The nozzle exit area is designed so that the exit pressure equals the ambient pressure at 30 km altitude. For the combustion gases, assume gamma is 1.22 and the molecular weight is 16. At an altitude of 30 km, where the local atmospheric pressure is 1186 Pa, calculate (a) the specific impulse, (b) the thrust, (c) the area of the exit, and (d) the exit Mach number

Expert Solution

samet mamat answered 2 years ago

Consider a rocket that burns steadily. The higher pressure in the combustion chamber, the faster the...

Consider a rocket that burns steadily. The higher pressure in the combustion chamber, the faster the propellant burns. Why is this? The relationship is such that the higher the pressure, the closer the gaseous flame is to the surface and the more effectively it can transfer heat back to the surface thereby gasifying the propellant quicker. The rate of gas generation, ?_? , can be described by the equation: ?_?=?_1 ?^?, where P is the pressure, and C1 and n...

Question 3 A sheathed thermocouple is placed in a combustion chamber to measure the temperature of...

Question 3 A sheathed thermocouple is placed in a combustion chamber to measure the temperature of the gases at a certain point in the process. The thermocouple reading is 1110K and the inside wall temperature was measured at 1008K. The thermocouple has a surface area of 10 mm2 . (a) A pitot probe is used to measure the velocity of the gas stream in the vicinity of the thermocouple tip. It measures a difference in static and dynamic pressure of...

A vehicle burns 150 mole/h of gasoline (C8H18) with 12% excess air in a combustion chamber...

A vehicle burns 150 mole/h of gasoline (C8H18) with 12% excess air in a combustion chamber with 90% fuel conversion. a) What is the molar flow of incoming air to the combustion chamber? (mol/h) b) What are the mass flows of the combustion products at the chamber’s exit? (g/h)

Determine the adiabatic combustion temperature at constant pressure and at constant volume for two of the...

Determine the adiabatic combustion temperature at constant pressure and at constant volume for two of the fuels of personal choice. Graphically show that this corresponds to the product temperature where the heat of reaction is zero.

methane gas CH4 enters a steady flow combustion chamber at 25 oC and 1 atm and...

methane gas CH4 enters a steady flow combustion chamber at 25 oC and 1 atm and is burned with 40 percent excess air, which also enters at 25 oC and 1 atm. After combustion, the products are allowed to cool to 25 oC. Assume complete combustion, determine the heat transfer per kmol of CH4

A small gas turbine uses C8H18(l) for fuel and it enters the combustion chamber at 25◦C...

A small gas turbine uses C8H18(l) for fuel and it enters the combustion chamber at 25◦C whereas air coming from the high pressure stage is at 287◦C . The products of combustion leave the combustion chamber at 1167◦C . The fuel is injected at a rate of 0.95 kg/min where it is mixed and burned with 400 % excess air. An analysis of combustions reveals that all the hydrogen in the fuel burns to H2O but only 90% of the...

Liquid Propane (C3H8(l)) enters a combustion chamber at 25 degrees C and 1 atm at a...

Liquid Propane (C3H8(l)) enters a combustion chamber at 25 degrees C and 1 atm at a rate of 0.4 kg/min where it is mixed and burned with 150% excess air that enters the combustion chamber at 25 degrees C. The heat transfer from the combustion process is 53 kW. Determine (c) the average specific heat at constant pressure of the product gasses, and (d) the temperature of the products of combustion.

A pressure vessel is being designed to hold compressed methane to fuel a liquid rocket motor...

A pressure vessel is being designed to hold compressed methane to fuel a liquid rocket motor at a maximum pressure of 50 bar. If the methane is to be stored at 40 bar, -18 C, determine the mass contained in a 10 m3 tank using the following assumptions: a) The ideal gas equation of state. b) The van der Waals equation of state. c) Using CoolProp. Comment on the accuracy of each.

Gaseous octane (C8H18) at 25 C, 1 atm enters a combustion chamber operating at steady state...

Gaseous octane (C8H18) at 25 C, 1 atm enters a combustion chamber operating at steady state and burns adiabatically with the stoichiometric amount of air entering at the same conditions. The combustion products consisting of CO2, CO, H2O(g), H2, O2, and N2 exit the combustion chamber at 2600 K and 1 atm. Determine the composition of the products. Draw a schematic of the problem and label with known information and list all appropriate assumptions. Hint: You have to solve two...

In a dual-combustion cycle, the maximum temperature is 2000 ?C and the maximum pressure is 70...

In a dual-combustion cycle, the maximum temperature is 2000 ?C and the maximum pressure is 70 bar. Calculate the cycle efficiency and the mean effective pressure when the pressure and temperature at the start of compression are 1 bar and 17 ?C, respectively. The compression ratio is 18/1. ANSWERS(63.7%; 10.54 bar)

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