MEEN 464 Exam 2 | UPDATED Questions with 100% Verified Answers
Question:
Consider a system in which the finite difference equation of
an interior node is given in its simplest form as: T*m =
2.54((rm1) (Tm1 Tm) (rm)(Tm Tm+1)) + Tm Note :
superscript is the end of a time step (or new time step) and no
superscripts is the beginning of a time step (or previous time
step). Which of the following is a correct statement about the
numerical analysis above?: Heat transfer is three-dimensional.
Heat transfer is two-dimensional. Heat transfer is
one-dimensional. Heat transfer in the system is steady state.
Answer:
Heat Transfer is One Dimensional
Question:
A cylinder with a 4 cm diameter hole drilled axially through
its center. The outer surface is insulated. Initially, the cylinder
is at a uniform temperature of 20 °C, and at time t=0, the
coolant from constant temperature bath at 100 °C flows through
the axial hole at a high flow speed. The radius of cylinder is
divided to 4 nodes. The nodal equation for node T1 was
derived using an explicit finite difference numerical method.
Note : superscript is the end of a time step (or new time
step) and no superscripts is the beginning of a time step (or
previous time step). Determine the temperature of node T1 in
°C after 10 sec when a time step ( ) 10 sec is used. Assume T0
is always 100 °C.
Answer:
26.67
Question:
We want to predict the temperature of the cylinder in question
2 at different condition. Now the initial temperature of the
, cylinder is 25 °C. Determine the temperature of node T1 in °C
after 10 sec when a time step ( ) 10 sec is used. Assume T0 is
always 100 °C.
Answer:
32.26
Question:
What is the heat exchanger rate for hot fluid?
Answer:
q_h = m_flow_rt*c_ph(T_hi - T_ho)
Question:
What is the heat exchanger rate for cold fluid?
Answer:
q_c = m_flow_rate_c*c_pc(T_co - T_ci)
Question:
What is the heat exchanger effectiveness defined as?
Answer:
e = q/q_max = m_flow_rt*c_p(T_hi -
T_ho)/m_flow_rt_min(T_hi - T_ci)
Question:
What is the number of transfer units (NTU) defined as?
Answer:
NTU = UA_s/C_min
Question:
How do you know if the heat exchanger is counter-flow?
Answer:
T_h2 > T_h1 and T_c2 > T_c1
Question:
Consider a system in which the finite difference equation of
an interior node is given in its simplest form as: T*m =
2.54((rm1) (Tm1 Tm) (rm)(Tm Tm+1)) + Tm Note :
superscript is the end of a time step (or new time step) and no
superscripts is the beginning of a time step (or previous time
step). Which of the following is a correct statement about the
numerical analysis above?: Heat transfer is three-dimensional.
Heat transfer is two-dimensional. Heat transfer is
one-dimensional. Heat transfer in the system is steady state.
Answer:
Heat Transfer is One Dimensional
Question:
A cylinder with a 4 cm diameter hole drilled axially through
its center. The outer surface is insulated. Initially, the cylinder
is at a uniform temperature of 20 °C, and at time t=0, the
coolant from constant temperature bath at 100 °C flows through
the axial hole at a high flow speed. The radius of cylinder is
divided to 4 nodes. The nodal equation for node T1 was
derived using an explicit finite difference numerical method.
Note : superscript is the end of a time step (or new time
step) and no superscripts is the beginning of a time step (or
previous time step). Determine the temperature of node T1 in
°C after 10 sec when a time step ( ) 10 sec is used. Assume T0
is always 100 °C.
Answer:
26.67
Question:
We want to predict the temperature of the cylinder in question
2 at different condition. Now the initial temperature of the
, cylinder is 25 °C. Determine the temperature of node T1 in °C
after 10 sec when a time step ( ) 10 sec is used. Assume T0 is
always 100 °C.
Answer:
32.26
Question:
What is the heat exchanger rate for hot fluid?
Answer:
q_h = m_flow_rt*c_ph(T_hi - T_ho)
Question:
What is the heat exchanger rate for cold fluid?
Answer:
q_c = m_flow_rate_c*c_pc(T_co - T_ci)
Question:
What is the heat exchanger effectiveness defined as?
Answer:
e = q/q_max = m_flow_rt*c_p(T_hi -
T_ho)/m_flow_rt_min(T_hi - T_ci)
Question:
What is the number of transfer units (NTU) defined as?
Answer:
NTU = UA_s/C_min
Question:
How do you know if the heat exchanger is counter-flow?
Answer:
T_h2 > T_h1 and T_c2 > T_c1
