An ideal Diesel cycle has a compression ratio of 17 and a cutoff ratio of 1.3. Determine the maximum temperature of the air and
the rate of heat addition to this cycle when it produces 140 kW of power and the state of the air at the beginning of the compression is 90 kPa and 578C. Use constant specific heats at room temperature.
1 answer:
You might be interested in
Answer:
1) In series, the combined head will move from point 1 to point 2 in theory. However, practically speaking, the combined head and flow rate will move along the system curve to point 3.
2) In parallel, the combined head and volume flow will move along the system curve from point 1 to point 3.
Explanation:
1) Pump in series:
When two or more pumps are connected in series, their resulting pump performance curve will be obtained by adding their respective heads at the same flow rate as shown in the first diagram attached.
In the first diagram, we have 3 curves namely:
- system curve
- single pump curve
- 2 pump in series curve
Also, we have points labeled 1, 2 and 3.
- Point 1 represents the point that the system operates with one pump running.
- Point 2 represents the point where the head of two identical pumps connected in series is twice the head of a single pump flowing at the same rate.
- Point 3 is the point where the system is operating when both pumps are running.
Now, since the flowrate is constant, the combined head will move from point 1 to point 2 in theory. However, practically speaking, the combined head and flow rate will move along the system curve to point 3.
2) Pump in parallel:
When two or more pumps are connected in parallel, their resulting pump performance curve will be obtained by adding their respective flow rates at same head as shown in the second diagram attached.
In the second diagram, we have 3 curves namely:
- system curve
- single pump curve
- 2 pump in series curve
Also, we have points labeled 1, 2 and 3
- Point 1 represents the point that the system operates with one pump running.
- Point 2 represents the point where the flow rate of two identical pumps connected in series is twice the flow rate of a single pump.
- Point 3 is the point where the system is operating when both pumps are running.
In this case, the combined head and volume flow will move along the system curve from point 1 to point 3.
<h2>Answer:</h2>
Rate of discharge in cumecs: <u>0.0048m³/s</u>.
Velocity flow: <u>24m/s</u>.
<h2>Explanation:</h2><h3>1. Find the rate of discharge in cumecs.</h3>
a. Convert from litres to m³.
120L*1000= 120000mL
120000mL=120000cm³
120000cm³/100³=0.12 m³.
b. Rate of discharge.
<em>If 0.12 m³ where discharged in 25 seconds, the rate of discharge is:</em>
0.12m³/25s = 0.0048m³/s.
<em />
<em />
<h3>2. Find the velocity flow.</h3>Let's refer to the fluid mechanics equation that relates volume flow, area and velocity. This is the formula:
; where the expression
is the volume flow rate (in m³/s); A is the cross-sectional area of the pipe (in m²), and v is the velocity flow (in m/s).
a. Solve the equation for v.
b. Calculate the cross-sectional area of the pipe.
<em>The cross-sectional area of the pipe is a circle. Hence, the formula of this area is:</em>
<em>We'll have to convert the diameter to meters, because the formula for flow velocity needs the area in m². Let's go ahead and do that.</em>
<em />.
<em>We were given the diameter, and the formula uses the radius, but the radius is just half of the diameter, therefore, we can substitute in toe formula like this:</em>
c. Substitute in the new expression for velocity flow and calculate.