Engine Definition and 999 Threads

  1. J

    Efficiency of engine taking diatomic ideal gas through cycles

    Homework Statement What is the thermal efficiency of an engine that operates by taking n moles of diatomic ideal gas through the cycle 1 -------> 2 -------> 3 -------> 4 ------> 1 shown in the figure ? http://s3.amazonaws.com/answer-board-image/2d50cb1e-1bc6-4325-acf6-fe1df4f0a7b5.jpeg...
  2. A

    Equation Questions for a gas powered engine driving a pulley system.

    I am building a prototype for an agricultural pulley system and I need help calculating how much horse power I need. The pulley system will need to drag a 400 lbs. object of a 45 degree incline for 150 feet. The static coefficient of friction is 0.1 and the kinetic friction is only 0.05...
  3. W

    Calculating Work and State Variables for an ideal Stirling Engine

    Homework Statement Consider the ideal Stirling cycle working between a maximum temperature Th and min temp Tc, and a minimum volume V1 and a maximum volume V2. Suppose that the working gas of the cycle is 0.1 mol of an ideal gas with cv = 5R/2. A) what are the heat flows to the cycle during...
  4. S

    Carnot heat engine - calculate work

    Using Carnot heat engine we connect two objects with the same mass m, specific heat capacities c. At the beginning the body 1 has temperature T_{1} and body 2 T_{2}. Calculate: a) How much mechanical work can this engine give? I tried like this, but i believe this is very wrong :(...
  5. D

    Carnot Engine Between Reservoirs with Varying Temperatures

    Homework Statement Two containers with fixed volume are each filled with n moles of a monatomic ideal gas with constant heat capacity. Initially, the volumes of gas are at temperatures T_1,i and T_2,i. What is the maximum amount of work that can be obtained by operating an engine between the...
  6. F

    Fixing 2-Stroke Engine Issues for C125R Honda Motor

    I am in the process of working on a 2 stroke motor that I am looking into converting to fuel injection. One thing in particular that I find with the 2 stroke is that is less efficient than than a 4 just because fuel mixture goes out the exhaust port while it is still open. Is there any ideas...
  7. S

    Recommendation for good book for IC Engine design

    Hey Everyone, I'm a mechanical engineering student and I was wondering if there was any good book regarding IC Engine design; which includes timing belt design, camshaft, crankshaft, rocker-arm, pump design etc.. a whole in one package that design engineers use for designing ic engines...
  8. P

    How Do You Calculate Qh for a Non-Carnot Heat Engine?

    1. Thot reservoir= 600K, Tcold reservoir= 300K, Output= 0.5 J of work for every J of thermal energy extracted from the hot reservoir. What is Qh? 2. efficiency= W/Qh; Carnot efficiency= 1- (Tcold/Thot); 3. I have found the Carnot efficiency to be 0.50. I don't know where to go...
  9. P

    Identify process in a heat engine

    Homework Statement I'm taking a practice test and I need some help with a heat engine problem. There are three parts, the one that's giving me trouble is a-->b. The Volume v. Pressure graph shows a straight line. Pa= 5 atm Va= 5 L Ta=300K and Tb=800K are given. So pressure is decreaseing...
  10. M

    Gas Turbine Engine Compressor Discharge Air Temperature Calculation

    Is this gas turbine engine compressor discharge air temperature calculation relatively accurate? Problem: Calculate the compressor discharge air temperature in ºF of the following gas turbine engine compressor core specifications. Gas Turbine Engine Compressor Core Specifications...
  11. D

    Quantifying impact of boost leak on a turbocharged engine

    Is there a general equation that can be used to determine the impact that a leak of a given size will have on a turbocharged engine? For example, if I know the expected boost for a given operating point (air mass through the system, pressure, temperature, etc) and I know the actual boost, can I...
  12. J

    Measuring mass flow rate into engine

    I have a motorcycle engine on a test stand and I need a way to measure the mass flow rate into the engine. It is currently carburated. I had two ideas off the top of my head. 1) build a venturi, and measure the pressure drop to figure out the velocity and therefore the mass flow rate...
  13. joe_cool2

    Heat engine: moles/temp unknown

    Homework Statement A heat engine uses the closed cycle shown in the diagram below. (Figure 1) The working substance is n moles of monatomic ideal gas. Find the efficiency of such a cycle. Use the values for pressure and volume shown in the diagram, and assume that the process between points...
  14. V

    How Is Efficiency Calculated for a Carnot Engine with Given Cycle Parameters?

    The problem: An engine puts an ideal monatomic gas through a clockwise rectangular cycle on a PV diagram with horizontal and vertical sides. The lower left point has a pressure of 1 atm and a volume of 1m^3 and the upper right point has pressure and volume three times greater. Calculate the...
  15. T

    Horizontal force exerted by an engine

    Homework Statement I am only confused about question 2. The Attempt at a Solution I decided to use bernoulli's equation to find velocity at point 1. With velocity at point 1 and point 2 I can use conservation of momentum to solve for the force exerted. In this case there would be Fx...
  16. I

    How Does Elastic Collision Affect Thomas the Tank Engine and Diesel?

    Thomas the tank engine and Diesel are involved in an elastic collision. A 2.5 kg Thomas is at rest but is approached head-on by a 5.0 kg Diesel moving at 0.60 m/s. The force-separation graph for the ensuing collision is given. FYI I am terrible with graphs, IDK WHY.. :frown: mT =...
  17. U

    What is the most fuel efficient Turbojet engine by pass ratio of A380?

    With four Rolls-Royce Turbojet engines attached on A380, I wonder, if the optimization of fuel efficiency as its prime design factor/variable? If so, may I know, what it is air by pass ratio?
  18. B

    How Do You Account for Member Weights in Crane Boom Statics Calculations?

    The 6575-lb engine is suspended from the crane boom. Assume the initial weight of members CD and AB to be 10lb/ft and 50lb/ft. Determine the resultant internal loadings acting on the cross section of the boom at point E. Also, find the joint reactions at A, C and D. So far I solve for the...
  19. C

    Carnot Engine ~ Electric Generating station

    Homework Statement An electric generating station is designed to have an electric output power of 1.4 MW using a turbine with two-thirds efficiency of a Carnot engine. The Exhaust energy is transferred by heat to a cooling tower at 110°C. a) Find the rate at which the station exhausts energy...
  20. A

    Automotive What is the optimal pump capacity for a 3-liter diesel engine?

    criteria to find oil pump capacity for engine , do anyone knows for diesel engine 3lits.
  21. V

    Could an ion engine attached to a satellite be used to stabilize orbit?

    Basically, my understanding is that every satellite that is not at a lagrange point will see its orbit eventually decay and it will crash back into the earth. Could an ion engine be set to fire at certain times to offset this? Because the rate of decay is slow, an ion engine might be up for it...
  22. P

    Why do different car engines need different engine oils? I assume viscosity

    Does a stronger engine need a higher viscosity fluid? What's the reasoning behind this?
  23. R

    F-35 Jet Exhaust: Supersonic Takeoff/Landing?

    When the F-35 is taking off or landing vertically, are any of the jet exhausts supersonic? I have seen the amount of thrust they produce but nothing about the Mach number. I am not looking for anything specific just whether or not the exhausts are supersonic.
  24. tsuwal

    Thermodynamics: Is Stirling engine reversible or irreversible?

    Stirling engine: the cycle is composed by two isothermals and 2 isometrica and there are just two heat reservoirs. By the isometrics I would say that that it is irreversible since you exchanging heat with a reservoir at a different temperature than your gas. However my notes say the...
  25. F

    Ice Sled Powered by Rocket Engine: Find t1, t2, v & Final Position

    An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at +38 ft/s2. After some time t1, the rocket engine is shut down and the sled moves with constant velocity v for a time t2. Assume the total distance traveled by the sled is 15750 ft and the total time...
  26. K

    Automotive My engine was smoking the other day

    I was stopped at a red light and there was some smoke coming out of the engine compartment of my car. There is also a slight burning smell. This is definitely not good. If you are a mechanic or automotive engineer, what is your take on this?
  27. Z

    Dimensionless analysis in engine cooling

    Hi, I have a problem with measuring cooling performance of a car on a chassis dynamometer. But maybe I should start with the theoretical part of my problem, namely with the dimensional analysis. If I have a physical system and I am interested in finding one variable as a function of all other...
  28. S

    Steam Engine Question - Help Understanding Needed

    Ok, so I have complete faith in the tried and proven laws of thermodynamics, including the part of the second law which states that it is impossible to create a heat engine working in cycle that takes in a certain amount of heat energy, and converts all the heat energy it takes in, into...
  29. M

    Several questions involving a homemade miniature jet engine.

    Hey guys. I am new to engineering and I came to this because I wanted to make my own miniature jet engine. I have a limited knowledge of physics but I wish to broaden it through this idea. Now I know that this was made before for RC models, but I want to actually make one so I understand how...
  30. T

    Automotive How Does Air Affect Engine Coolant Performance?

    Hello, my question is about air in engine cooling systems. Coolant is formulated to resist boiling, and furthermore kept under pressure to increase its boiling point. I think this is to control its phase. In other words we must prevent coolant from boiling (vaporizing) because vapor does...
  31. M

    Achieving VTOL with jet engine instead of rocket engine

    Jetpack International's T-73 achieves vertical takeoff with an actual jet engine as opposed to the rocket engines used by the majority of jetpack models. This allows it to have longer flight time (9 minutes as opposed to 30 seconds). Some fighter planes also manage VTOL with a jet engine, the...
  32. F

    Exhaust and engine accoustics for asthetics and performance

    This is all in relation to a 90 degree v8 I am looking for the highest frequency/note/tone/pitch I can get. I very much enjoy the higher, crisper, cleaner sound the european v8 makes. I hate with a passion the rumble of the harley/dumptruck American v8. I have heard flowmasters on these cars. I...
  33. P

    Is making photon Engine possible ? :A different thought to power space craft

    Is making photon Engine possible ? :A different thought to power space craft! Now a days Scientists are working on photon engine. They are trying to power engine from light. Thought is looks great but there is practical engineering problems with it. Ya it is true that photons have momentum...
  34. mrspeedybob

    The maximum theoretical efficiency of a heat engine

    http://en.wikipedia.org/wiki/Heat_engine This is one of those threads where the OP proposed a device which will not work and hopefully by the end understands why. So here's the device... Air enters through a long intake tube. At the end of the tube it enters a combustion chamber where fuel is...
  35. P

    Engine Heat Input Vs Torque Vs Power

    Hi all, I am trying to compare the heat input into an engine with useful work out. I have taken a measurement for Torque, and have calculated heat input per cylinder based on combustion calculations i.e throttle % x cal value of fuel x fuel mass. I am happy with the heat input...
  36. B

    Flywheel design. Inertia dyno for 745 KW engine.

    Hello again, I am currently designing a flywheel for a 745 KW engine inertia dyno. Basically my design requirements are so: Max RPM: 530 RPM (=55.5 rad/s) Flywheel Diameter: 1.7 meters Time needed to accelerate: 60 second (to max rpm) I need help determining the mass of the...
  37. MacLaddy

    Thermodynamics- Heat engine and refrigeration

    Homework Statement A nuclear power plant generates 2000 MW of heat energy from nuclear reactions in the reactor's core. This energy is used to boil water and produce high-pressure steam at 300° C. The steam spins a turbine, which produces 700 MW of electric power, then the steam is condensed...
  38. A

    Automotive Exploring the Possibilities of an ALTICE Engine

    Aloha, This is my first post, I am happy to be here. Would there be any advantage to a internal combustion engine(ICE) that fired two pistons simultaneously? This would be an alternate-firing ICE that would fire the pistons in pairs every 180º, instead of one piston fire and the other...
  39. A

    Mutations: evolution’s engine becomes evolution’s end?

    Mutations: evolution’s engine becomes evolution’s end!? Did scientist Alex Williams really disprove evolution? is he right ? is there a reply to his topic ? i need to understand how does this make mutations evolution’s end ! Mutations: evolution’s engine becomes evolution’s end! by Alex...
  40. B

    Testing a 100lbf Jet Engine: Blast Shields

    Hey guys. As the title reads, I am a part of a research project and we will soon be testing a 100lbf jet engine. We take safety very seriously and want to take all the proper precautions in order to ensure everybody involved will come out of the experimentafely in case something goes wrong...
  41. Q

    What Are the Names and Materials of Chainsaw Engine Components?

    Just wondering what the name of the component as a whole is? And what is it made of? Also, if you could tell me the name of all the constituent parts, that would be great...
  42. P

    C/C++ [C/C++] need a bit of help making a simple search engine.

    Hi, new to the forum, it is a really spiffy place. I'm not really much of a programmer, but I have an interest in it and kind of like to piddle around with programming. I am learning C and C++ mostly by doing, browsing books, and asking dumb questions of people who know a lot more about it than...
  43. F

    Will curved heat pipes improve Stirling engine efficiency?

    Stirling engines use regenerators(heat pumps) to recover heat and increase their efficiency.The basic problem here is "The regenerator constitutes a (dead) volume which thwarts the benefit of its presence.There is never absolute truth" I believe I have a working concept of the heat pipe.My idea...
  44. S

    Hydrogen and oxygen used as fuel in internal combution engine

    why cannot hydrogen and oxygen not used in internal combution engine as fuel? it would be pollution free.
  45. L

    What happens when you increase air temperature flowing into an engine?

    Hi for a bit of work I have to explain the advantages and disadvantages of a higher engine intake air temperature. I have been told that it decreases the power output of the engine but I can't seem to work out why it would decrease. I also want to comment on how it affects the efficiency but...
  46. A

    Carnot Efficiency of a heat engine

    My problem only gives me joules to work with. Is it possible to convert from joules of energy to temperature (Kelvin)?? If so how?
  47. D

    Finding the efficiency of an engine given energy input, energy wasted.

    Homework Statement An inventor claims to have developed an engine which takes in 1.1x108J of heat energy at 400K, and rejects 5.0x107J of heat energy at 200K. Would you advise investing in this project? Explain your answer. Homework Equations W = Q1 – Q2 η = W/Q1 = 1 – Q2/Q1 The...
  48. C

    How is a wankel engine lubricated?

    i was admiring its animation like when this popped into my head. any answers? also anybody know any latest developments in lubricating closed off engines?
  49. M

    Automotive How Do You Calculate the Flow Rate for a Diesel Engine Oil Pump?

    Hello Gentlemen, Do you help me in finding flow rate calculation for diesel engine oil pump? Is anyone know procedure need follow based nominal clearance / maximum clearance? How we can find flow rate requirement for engine.
  50. N

    Heat Engine Cycles: Understanding Reversible Changes

    Homework Statement Taken from adkins Introduction to thermal physics A reversible heat engine is operated between two bodies, one of heat capacity C1 initially at temperature T1 and the other of heat capacity C2 initially at temperature T2. As the engine operates, the warmer body gradually...
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