Problem 1.¶
The figure is a schematic of a horizontal water jet from a tank at 70 $^oF$ exits from a circular orifice and strikes a vertical plate that is normal to the axis of the jet.
A 600 lbf force is required to hold the plate in place against the jet; the pressure in the tank at point A is 25 psig. What is the diameter of the jet downstream of the orifice?
# sketch here
# discussion
Direct application of bernoulli's equation and momentum
Problem 2¶
The figure is a schematic of a turbofan engine. On an airframe the engine takes in air, a portion of which passes through the compressor into the combustion chamber where fuel is added and ignited, and out through the turbine; the remainder of the air bypasses the compressor and is accelerated by the fans. The mass flow rate of bypass air to the mass flow rate through the compressor-combuster-turbine path is called the “bypass ratio.” The total flow rate of air entering the turbofan engine is 412 kg/s with a velocity relative to the engine of 400 m/s. The engine has a bypass ratio of 6.1:2. The bypass air exits at 660 m/s, whereas the air through the compressor-combustor-turbine path exits at 990 m/s.
Determine:
- The thrust (in Newtons) generated by the turbofan engine
# sketch here
# list known quantities
# list unknown quantities
Thrust!
# governing principles
- Momentum
- Continunity
# solution (step-by-step)
Now insert this problem's values - maybe a script to help!
bypass = 6.1/2
massflow = 412
v_inlet = 400
v_jet = 990
v_bypass = 660
m1 = massflow/(1+bypass)
m2 = massflow-m1
F = m1*v_jet+m2*v_bypass-(m1+m2)*v_inlet
print("Thrust is : ",round(F/1000,3)," kN to the LEFT")
# discussion
Direct application of momentum