What is Engine: Definition and 999 Discussions

An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a heat engine, in which heat from the combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston, which turns a crankshaft. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and ultimately motion.

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  1. H

    What Size Bolt Do I Need for 10,000 ft/lbs of Torque on a 1.25 inch Drive Axle?

    If a gas engine makes 20 hp at 3000 rpm I figure the ft/lbs of torque equals about 460. Negating friction if the drive axle the engine turns goes 10 rpm with 20 hp the ft/lbs of torque equals about 10,000. I was using the formula hp x 5252 divided by rpm of shaft What I need to know...
  2. T

    Can We Calculate Ramjet Thrust Using Combustion Mach Number and Rayleigh Flow?

    For a ramjet engine, combustion occurs at a finite Mach number M. If we know the ambient conditions like free stream Mach number and pressure and the ratio between the stagnation temperature at the inlet and exit of the combustor, how can we derive the thrust? How can we incorporate the...
  3. Feodalherren

    Thermodynamics - Stirling Engine

    Homework Statement In 1816, Robert Stirling, a Scottish clergyman, patented the Stirling engine, which has found a wide variety of applications ever since. Fuel is burned externally to warm one of the engine’s two cylinders. A fixed quantity of inert gas moves cyclically between the...
  4. marellasunny

    Engine map with load curve in 5th gear:fuel consumption varies weirdly

    http://imageshack.com/a/img824/2641/1cpe.png The black curve I drew there represents the load curve in 5th gear. Why is it that at 5500 rpm(160kph), I have a lesser fuel consumption(270g/kWh) than at 4000 rpm(280g/kWh)? Intuitively,if I produce more power at 180kph(ie 5500rpm),I should...
  5. A

    Why there is no different opportunities in engine technology?

    This is something pretty new, why do you think that nobody take the risk to build it, up to these days? I was looking for different concepts and saw few projects from MIT, some quasiturbine projects, some liquid piston engines, doyle engine. But let's face it - too complicated, now these videos...
  6. A

    Design of forced ventilation system for gas reciprocating engine

    Here is the real life problem I am facing: Gas reciprocating engine is situated in an engine room. The engine is primarily cooled by jacket water flowing to remote radiator. The engine surface must also be cooled by forced convection to maintain max air inlet temp of 40C. Ambient can reach as...
  7. A

    Why adiabatic process is required in heat engine?

    what is the need of adibatic process in heat engine? We can work only with isothermal process .Please expalin this.
  8. E

    A Carnot engine using methane

    Homework Statement A Carnot engine operates with 1 kg of methane, which we will consider an ideal gas. The ratio of specific heat capacities \gamma is 1.35. The ratio of maximum volume to minimum volume is 4 and the cycle efficiency is 25%. Find the entropy increase during the...
  9. V

    What are the necessary parameters for designing an IC engine?

    hey i am engineering student i am interested in designing a ic engine. I want to know necessaries and parameters for designing a engine hey please provide some reference for it thank you:smile:
  10. A

    Is the efficiency of heat engine more in hilly areas than in plains?

    In hilly areas temp is low than plain areas.So the temperature of source as well as sink must be low.But ratio remains same.So efficiency is same as in plain areas? Is my logic correct? Or anything else? Can it be more?
  11. A

    Aircraft engine specifications

    Hello, I'm doing a full stress analysis on a complete aircraft engine. so i was looking for documents with full specifications of the engine ( blueprints,charts,data tables, ...etc. ) . I know that most of these information are top secret whether it's a civil engine a military engine. However...
  12. Glurth

    Sterling Engine- Pump variant: will it work?

    I've been wracking my brain for a simple way to implement a Sterling Engine as a water pump, rather than an engine, and using solar power as a heat source, rather than a flame. The attached diagram is the simplest implementation I could come up with: Rather than pushing/pulling a piston...
  13. P

    Using EFI to make a larger engine perform like a smaller one

    So I was having a discussion with a fellow motorcycle racer and he stated that The bike I'm riding has too much horsepower for my skill level. I currently ride a 1000cc gsxr1000. He suggested I sell the bike and get a 600cc gsxr600. Well I love my liter bike and even though he's probably right...
  14. gfd43tg

    Carnot Engine with finite reservoirs

    Homework Statement A Carnot engine operates between two finite heat reservoirs of total heat capacity CtH and CtC. a) Develop an expression relating TH to TC at any time. b) Determine an expression for the work obtained as a function of CtH ,CtC , TH and initial temperatures TH0 and TC0...
  15. S

    Discover the Best Brake System for a 70Kw Engine Dyno Design

    Hi all, I'm designing a 70Kw engine dyno and I'm thinking to use a friction brake with a pneumatic actuation. Which kind of brake system usually have such commercial engine dyno? Eddy current brake? Hydraulic one? Thanks
  16. R

    Thermodynamics Heat Engine

    Homework Statement A haet engine works based on the difference of the temperature at the top and bottom of the ocean. The machine is solar powered and the average solar irradiance is 240W/m^2 and the temperature at the surface of the water is 25ºC. Calculate the temperature at the bottom of...
  17. C

    Change in entropy of a heat engine

    Homework Statement One end of a metal rod is in contact with a thermal reservoir at 695K, and the other end is in contact with a thermal reservoir at 113K. The rod and reservoirs make up an isolated system. 7190J are conducted from one end of the rod to the other uniformly (no change in...
  18. C

    Heat Efficiency of a Carnot Engine

    Homework Statement A Carnot engine operates between a warmer reservoir at a temperature T1 and a cooler reservoir at a temperature T2. It is found that increasing the temperature of the warmer reservoir by a factor of 2.00 while keeping the same temperature for the cooler reservoir increases...
  19. jmex

    Eco-Friendly Hydrogen Engine Project

    Hello PFs, (It should be eco-friendly project) I am working on ICE using hydrogen fuel. My very first step is to produce hydrogen from water that i have achieved by electrolysis.(hope to see another method as i have heard one to produce from sunlight) I am using this hydrogen and oxygen...
  20. A

    Thermodynamics - Heat Engine Cycle

    Homework Statement n = 5 moles, monatomic, ideal gas p1 = 7280 Pa; v1 = 2 m3 p2 = 7280; v2 = 6 p3 = 6500; v3 = 6 What is the change in heat, from 2 to 3, and from 3 to 1? Homework Equations PV = nRT U = (3/2)nRT Q = du + dw The Attempt at a Solution PV = nRT (7280)(2) =...
  21. V

    Small Engine Dyno: Designing & Attaching Torque Arm

    I am currently in the process of designing an engine dynamometer for a small engine. Maximum power of 1 KW @ 7000 RPM and a maximum torque of 1.6 Nm @ 5500 RPM. Here is my proposed method, but I have some concerns that I'll state below: Prony Brake Essentially a friction dyno, I would...
  22. J

    Is a Sun-Solar Cell System Truly Equivalent to a Carnot Engine?

    I have undertaken a course on Semiconductors. My professor told us that a sun-solar cell system can be taken as a Carnot Engine. He assumed that the surface temperature of sun is 6000k and that of solar cell is 300k.And then he found out the efficiency by (1-T1/T2), which came out close to be...
  23. E

    Tolerance for gas/steam Engine

    What is the standard tolerance for a cylinder bore and piston? The working fluid is steam or compressed air.
  24. I

    Turbine engine burner can hole size

    Im building a turbine engine and I am having trouble figuring out the hole sizes for the burner can, my problem is that I am not using a compressor section but rather using an air compressor for the air intake so I can't use the standard formula, can I? If I know my blad diameter and the flow...
  25. binbagsss

    Thermodynamics, engine cycles , entropy, concepts.

    Okay, I am considering a cycle, where the working fluid is an ideal gas, with heat capacities Cv and Cp, the cycle consists of: isochoric increase in volume, adiabatic expansion back to initial pressure and a isobaric compression back to initial conditions. Questions: - q1) I am asked to...
  26. A

    How do you make a realistic physics engine?

    Here's what I need, and this might sound far-fetched, but please answer it to the best of your ability. I want to create a car engine in blender, and then add a physics engine to make it run. The thing is, I don't want to animate it, I want to apply python script that can actually make the...
  27. A

    Can someone explain this engine to me?

    Here are the links http://books.google.ca/books?id=RN4_jLbVO3YC&pg=PA50&dq=Stirling+auto+engine+a+lot+of+progress,+but+Spirit&redir_esc=y#v=onepage&q&f=true http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880002196_1988002196.pdf I have read both but I don't understand how the gas...
  28. G

    Internal combustion engine calculations.

    Hello everybody, I am working on the whole vehicle calculations, engine, brakes, suspension and engine simulation, using that software, take a look: http://www.speed-wiz.com/calculations/engine-simulation/engine-simulation-conditions.htm That software, you input the values at the top...
  29. A

    How do you measure the force of a Stirling engine?

    I was wondering how the force of a Stirling engine was measured? I mean, for every degree Celsius that the temperatures differ. how much more force (or horse power) is the engine generating? Are there any other variables to this? What I'm getting is can Stirling engines power cars if enough heat...
  30. junfan02

    Carnot Engine: Finding Final Temperature Attained

    A Carnot engine is operating between a source and a sink at temperatures T1 & T2 (T1>T2) respectively.. The heat capacities of the source and the sink are equal. Find the final temperature attained.
  31. I

    What is the optimal blade angle for a turbine engine?

    Hello, so I am building a small turbine engine and i need to know the best angle for the blades. Any help would be very helpful, thank you.
  32. I

    Required force to rotate the Engine piston

    Dears, please help me: How to Calculate the Required Force to Push the Car Engine Piston Down if I Want to Rotate my shaft in 1500rpm, My Piston Dia Is 50mm, Piston Hight Is 100mm, Piston Mass Is 1kg, My Engine Is 4cylender and 4stroke? regards ibrahim
  33. M

    Understanding Combustion: Exploring the Role of Charge in Engine Efficiency

    Homework Statement combustion adds 1200kj/kg to the charge. what is the meaning of " charge" here. Homework Equations The Attempt at a Solution
  34. M

    Exploring Engine Thermodynamics: A Comprehensive Resource Guide

    I need sources such as web sites, books, or videos aiming engine thermodynamics subject such as otto cycle,diesel cycle, seilinger cycle(combination of diesel and otto), performance, combustion process. Can you make give some advice.
  35. C

    Understanding Heat Engines: Exploring the Second Law of Thermodynamics

    Hi, I am trying to figure out heat engines. I don't understand why heat from a hot reservoir MUST exhaust heat into a cold reservoir. How does that satisfy the second law of thermodynamics? Why can't all energy from the hot reservoir be used to do work? Thanks
  36. K

    Unlocking the Power of BMW Engines: Bore, Stroke, CC, & More

    I always wonder how BMW engines of smaller size are powerful than other OEM's engines despite other OEMs haveing engine of larger size. To be very clear i have following questions.. 1. Doesnt size of engine affects the power of the engine? 2. What influences the power of engine...? Bore...
  37. M

    Correct clearance of engine parts

    hello friends,can you explain what is correct clearance of engine's moving parts,giving examples.
  38. M

    Calculating Cooling Load of a Car Engine: Where to Begin?

    Homework Statement hello friends,i have to do a project about calculations of cooling of a car engine.i don't know what to do or where will i start.can you offer me some links or books about this area please.how can i find how many wats of heat, say, a 100 kw engine, releases. Homework...
  39. O

    What Are Some Good Search Engines That Prioritize Keyword Accuracy?

    I'm fed up with google. It returns results that don't have all my keywords in it. Just now I searched for "Skyrim Playonlinux" and it returned several top results involving Skyrim Wine (wine as in drink, in the game), since Wine is related to playonlinux. What is a good search engine that...
  40. voltech444

    Could a Reverse Uni-Flow Engine Revolutionize the Automotive Industry?

    Hello This is a concept I have been researching for a while. A company called LIM Technology has made a few working prototypes of this very concept they call a simple cycle engine; they have a patent for the intake valve technology. Here is their website...
  41. S

    Problem Involving a 2 stroke IC engine

    Homework Statement A two-stroke internal combustion engine can be modeled by the following cycle. The cycle starts with the piston chamber at maximum volume V1 = 1000 cm3, filled with an air-fuel mixture – which we treat as an ideal gas – at atmospheric pressure and room temperature (p1 =...
  42. S

    Help with engine displacement volume, fuel flow rate and crank angle

    Homework Statement An automobile has a 2.5-litre, four-cylinder, homogeneously charged, direct injected, four-stroke diesel engine. The maximum power output of this naturally aspirated engine is 200 HP at 4000 rpm. By turbocharging, the intake pressure is boosted twice as that for the naturally...
  43. H

    Heat transfer of a tank connected to Sterling Engine

    Have a new task, would appreciate some pointers. Conducting a heat transfer analysis on a tank with water coming in and out that's to serve as a hot side for a displacing stirling engine. If the inlet q dot into the tank is 1000W. Observing there will be losses due to conduction and...
  44. W

    Compressed oxygen for jet engine (?)

    as jet engines lose there productivity at altitude due to thining air/oxygen , why isn't injecting compressed air directly along side the fuel a good idea ? , is this already being done ? would /does this not increase ceiling height and allow sub orbit levels or possible leave atmosphere...
  45. J

    MHB Physics Engine Pump problem

    An engine pumps water from a river 10m below its own level and discharges it through a nozzle of diameter 10cm with a speed of 50ms^-1. Find the power required assuming (a) no losses. (b) 70% efficiency. Water weighs 10^3kgm^-3. (g = 10ms^-2) Please help me with this problem, I've bever come...
  46. S

    Using Fluid mechanics to rate power output of an engine.

    I trying to come up with a way to measure the power output of an engine using a water pump, And I wanted some one to go over my math and check for flaws in my thoughts. My idea is to measure the flow rate and the pressure of the output of the water pump. Using this math to solve for power...
  47. S

    Choosing the Right Turboprop Engine for Light Aircraft

    Hi, I'm a third year student studying mechanical engineering under going a third year dissertation. My individual project consists of designing a light aircraft, however I have ran into a few issues. I want to import a turboprop engines for my 4 person light aircraft. Following that I am...
  48. R

    Otto Cycle Engine Homework: Total Work & Efficiency Calculation

    Homework Statement "A car has a six-cylinder Otto-cycle engine with compression ratio r = 10.6. The diameter of each cylinder is 82.5 mm. The distance that the piston moves during the compression stroke (see fig. 1) is 86.4 mm. The initial pressure of the air-fuel mixture (at point a in...
  49. Z

    Jet Engine performance in Cold Weather

    Hey guys. I was studying up jet-engines and their performances with varying ambient temperatures and found myself stuck on something that is probably very trivial. What I've read online and in my notes is all generally the same - that as temperature falls air density rises and as such more...
  50. S

    Engine thermal efficiency and Volume ratios

    The question: A perfect gas undergoes the following cyclic processes: State 1 to 2 cooling at constant pressure. State 2 to 3 heating at constant volume. State 3 to 1 adiabatic expansion. Deduce an expression for the thermal efficiency of the cycle in terms of r the...
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