An idealized diesel engine operates in a cycle known as the air-standard diesel cycle shown in Figure P21.19. Fuel is sprayed into the cylinder at the point of maximum compression, B. Combustion occurs during the expansion B→ C, which is modeled as an isobaric process. Show that the efficiency of an engine operating in this idealized diesel cycle is 1(T, e = 1 T. T, B P Adiabatic B C processes D A -V V2 = VB Vc V = VA Figure P21.19

An idealized diesel engine operates in a cycle known as the air-standard diesel cycle shown in Figure P21.19. Fuel is sprayed into the cylinder at the point of maximum compression, B. Combustion occurs during the expansion B→ C, which is modeled as an isobaric process. Show that the efficiency of an engine operating in this idealized diesel cycle is 1(T, e = 1 T. T, B P Adiabatic B C processes D A -V V2 = VB Vc V = VA Figure P21.19

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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Problem 5: Suppose a Carnot engine has an efficiency of 45 % and a cold reservoir temperature of 28.5°C. Part (a) What is the hot reservoir temperature, in degrees Celsius, of this Carnot engine? Part (b) What must the hot reservoir temperature be, in degrees Celsius, for a real heat engine that has an efficiency of 45, which is 70% of the maximum efficiency? Assume it has the same cold reservoir, at 28.5°C.
Consider the following thermodynamic cycle for an ideal gas: From A to B the gas is compressed adiabatically. From B to C heat Qh is added to the gas and the gas is kept at constant volume. From C to D the gas expands adiabatically. From D to A the gas ejects heat Q₁ to the environment and is kept at constant volume. (1) Draw the PV-diagram associated to this cycle. (2) Show that the efficiency of an engine running this cycle is given by e = 1 - (3) Calculate the efficiency for a compression ratio VA/VB = 8 assuming a diatomic gas. [Hint: for a diatomic gas Cv = (5/2)R.]
What is the thermal efficiency of a Carnot cycle operating between 52oC and 352oC? 84% 56% 48% 15% none of the listed values. 73%
In one cycle a heat engine absorbs 520 J from a high-temperature reservoir and expels 310 J to a low-temperature reservoir. If the efficiency of this engine is 57% of the efficiency of a Carnot engine, what is the ratio of the low temperature to the high temperature in the Carnot engine? Tlow Thigh =
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(a) What is the hot reservoir temperature (in degrees C) of a Carnot engine that has an efficiency of 40.0% and a cold reservoir temperature of 32.5°C ? °C (b) What must the hot reservoir temperature (in degrees C) be for a real heat engine that achieves 0.750 of the maximum efficiency, but still has an efficiency of 40.0% (and a cold reservoir at 32.5°C )? °C
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