Question

In: Mechanical Engineering

6.5 An engine manufacturer has decided to change one of its engines from a spark ignition...

6.5 An engine manufacturer has decided to change one of its engines from a spark ignition type to a compression ignition type. If the swept volume is unchanged, what effect will the change have on:

(i) maximum torque?

(ii) maximum power?

(iii) the speed at which maximum power occurs?

(iv) economy of operation?

Solutions

Expert Solution

(i) Maximum torque will decrease . This is beacuse the swept volume is not changed, so the diesel will not get enough compression in order to burn properly and the heat produced will be less. So enough torque will not be generated.

(ii) As Power = 2πNT/60

So the product of torque and speed will decide whether the power has increased or not. Now as the torque is already decreased so the maximum power will also decrease.

(iii) Converting SI to CI will reduce the speed at which maximum power will occur.

(iv) Overall economy of operation will decrease as the efficiency of fuel is highly reduced due to incomplete combustion.

samet mamat answered 2 years ago
Next > < Previous

Related Solutions

A reputable engine company has been making carbureted spark-ignition engines that operate with an equivalence ratio...
A reputable engine company has been making carbureted spark-ignition engines that operate with an equivalence ratio = 1.0 and a compression ratio of 9:1 for years. In order to control emissions, the engines operate with 20% exhaust gas recirculation (EGR) and a three-way catalytic converter. Since the company’s market share is steadily dropping, they consider hiring a MEC graduate to rescue them. The ambitious young engineer proposes a port fuel-injected (PFI) design, which operates lean at 0.7 with a high...
One method for reducing the pumping work in throttled spark-ignition engines is early intake valve closing...
One method for reducing the pumping work in throttled spark-ignition engines is early intake valve closing (EIVC). With EIVC, the inlet manifold is held at a pressure pi, which is higher than the normal engine intake pressure pi*. The intake valve closes during the intake stroke. The trapped fresh charge and residual is then expanded to the normal cycle (lower) intake pressure, pi*. You can assume that both cycles have the same mass of gas in the cylinder, temperature and...
One method for reducing the pumping work in throttled spark-ignition engines is early intake valve closing...
One method for reducing the pumping work in throttled spark-ignition engines is early intake valve closing (EIVC). With EIVC, the inlet manifold is held at a pressure pi, which is higher than the normal engine intake pressure pi*. The intake valve closes during the intake stroke. The trapped fresh charge and residual is then expanded to the normal cycle (lower) intake pressure, pi*. You can assume that both cycles have the same mass of gas in the cylinder, temperature and...
A vehicle which is equipped with a 6 cylinder, 2000 cc spark ignition engine is cruising...
A vehicle which is equipped with a 6 cylinder, 2000 cc spark ignition engine is cruising at an average speed of 150 km/h from Ankara to Istanbul on the highway. The mass of the vehicle with single driver is 1200 kg and its projected frontal area is 3 m2. The coefficient of rolling resistance is 0.015 and the discharge coefficient is 0.3. The distance between Istanbul and Ankara is approximately 450 km. Assuming an average brake specific fuel consumption of...
1- You need to analyze the operation and performance of a four-stroke, spark-ignition internal combustion engine...
1- You need to analyze the operation and performance of a four-stroke, spark-ignition internal combustion engine (automobile engine). a- Would you analyze the engine as an Open System or a Closed System? b- How many properties of the engine exhaust would you need to measure in order to determine the Thermodynamic State of the exhaust gas? c- Identify a set of properties of the exhaust gas that you might measure to establish its state. d- Are these properties Intensive or...
The “cold start ignition time” of an automobile engine is investigated by a gasoline manufacturer. The...
The “cold start ignition time” of an automobile engine is investigated by a gasoline manufacturer. The following 8 times (in seconds) were obtained for a test vehicle: 1.75, 1.92, 2.62, 2.35, 3.09, 3.15, 2.53, 1.91 A Construct and interpret the 95% confidence interval for the population mean start ignition time of an automobile engine. B Test at 0.05 significance level whether the population mean start ignition time is below 2.9 
seconds. Include the hypotheses, the test st atistic, the p-value,...
Isooctane is supplied to a four-cylinder spark-ignition engine at 2 g/s. Calculate the air flow rate...
Isooctane is supplied to a four-cylinder spark-ignition engine at 2 g/s. Calculate the air flow rate for stoichiometric combustion. If the engine is operating at 1500 rev/min, estimate the mass of fuel and air entering each cylinder per cycle. The engine displaced volume is 2.4 liters. What is the volumetric efficiency?
Problem 1: A 5.2-liter, spark-ignition, four-stroke cycle, V6 automobile engine operates at 2400 RPM with ?...
Problem 1: A 5.2-liter, spark-ignition, four-stroke cycle, V6 automobile engine operates at 2400 RPM with ? = 1.5. The engine has a volumetric efficiency of 89%, with bore as B = 2.1 S. The density of air at room temperature is 1.18 kg/m3. Lamda = 1.5 Calculate: Stroke length (m and cm) Average piston speed (m/sec) Mass flow rate of air into engine [kg/sec] Mass flow rate of fuel into engine [kg/sec]
The "cold start ignition time" of an automobile engine is being investigated by a gasoline manufacturer....
The "cold start ignition time" of an automobile engine is being investigated by a gasoline manufacturer. The following times (in seconds) were obtained for a test vehicle: 1.76, 1.84, 2.71, 2.26, 3.15, 3.21, 2.48, 1.87. A second formulation of the gasoline was tested in the same vehicle, with the following times (in seconds): 1.75, 2.08, 3.17, 3.21, 2.74, 2.83, 3.47, 2.47, 1.98, and 3.39. Use this new data along with the cold start times to construct comparative box plots. Construct...
Lakeview Engine, Inc., produces engines for the watercraft industry. An outside manufacturer has offered to supply...
Lakeview Engine, Inc., produces engines for the watercraft industry. An outside manufacturer has offered to supply several component parts used in the engine assemblies, which are currently being produced by Lakeview. The supplier will charge Lakeview $320 per engine for the set of parts. Lakeview’s current costs for those part sets are direct materials, $160; direct labor, $75; and manufacturing overhead applied at 100% of direct labor. Variable manufacturing overhead is considered to be 20% of the total, and fixed...
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT