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. Maor Hadad

    Position of a train engine (Locomotive)

    Hi, I have a question about where's the most efficient place for a train engine - Let's say a train has to do a some route back and forth, the route has curves and positive and negative slopes. In real life - What's the best position for the enginge? My intuition says it will be most efficient...
  2. randini

    High temperature insulating material for new engine concept

    In the past, reciprocating engine platforms have prevented the use of thermal insulating materials like ceramics due to, among other reasons, abrasion and vibration. One of the problems in the past has been the movement of the piston and piston rings over the cylinder wall where the insulating...
  3. N

    Calculating Work Done by Car Engine

    Homework Statement A car (mass 900 kg) runs 12 km along a level road at a constant speed of 80 km / h. The friction force is 500N. Calculate the work done by the engine Homework Equations W= F x displacement[/B]The Attempt at a Solution W= (900x 9.81) N x 12000m W=10594800 J But this is...
  4. Monsterboy

    Mean effective pressure in a diesel engine

    Homework Statement Air enters a diesel engine with a density of 1.0 kg/m3. The compression ratio is 21 .At steady state ,the air intake is 30 x10-3 Kg/s and the net work output is 15 kW .The mean effective pressure (in kPa) is ... Homework Equations Pm= W.D/ Vs...
  5. Z

    Is the coil the only viable shape for an electric engine ?

    Hi, I'm an hobbyist right now I'm into electric engines, simple engines for low voltage and low current applications; I have noticed that there are many variations about how and what an electric engine can do even considering only DC motors, but basically all the engines that I have examined up...
  6. C

    Pressure and flow in pipe and engine

    I Think this is Good Platform to discuss My Problem Can you Please guide me how to create mathematical model for System of Air Pipe -Engine-and Force on Piston As in My case i want to build mathematical model for system in Which air is Flowing from pipe say 2.8 K/s and its enter in the valve to...
  7. E

    Estimating Wheel Torque From Engine Torque

    It seems possible to obtain engine torque and RPM from a truck CAN bus. I'd like to estimate tractive force at the wheels given these two values. How should I go about computing torque at the wheels? Wouldn't I need gear ratio, which doesn't seem obtainable from the CAN bus? Do I need to...
  8. J

    Why did my engine suddenly blow up?

    hi all. I am new to this forum and have a question i hope someone can shed some light on. im trying to determine, if possible, step by step why my motor blew up. here goes. its a 20 y.o. 4cyl mazda diesel i had the motor rebuilt 2 years ago by a professional. it had a 1 year warranty so well...
  9. LtIvan

    How to Design the Complex Shapes of a Rotary Engine

    Allo, this is my first post here. I must say this forum has everything not just Physics but Mathematics and Engineering, all my favorite things. Introduction: I would like to start with an introduction of a 'rotary engine' for those who don't know. Unlike the common boxer piston engine with...
  10. Y

    Can Isopropyl Alcohol Be Used as Fuel for Rocket Engines?

    Y'know, just because. Will it be possible to create a rocket engine using isopropyl alcohol as fuel? Why or why not? (will be used just for show and not really for sending ships to space. I'd rather have an entire school intact than it being blown to bits if I used hydrogen)
  11. S

    Dual cycle-Diesel Engine question

    Homework Statement A diesel engine works on the dual combustion cycle and has a compression ratio of 20/1. At the beginning of the compression process the pressure and temperature are 1.0 bar and 22°C respectively. In the cycle, heat is added at constant volume until the pressure has increased...
  12. O

    Searching for a Gasoline Engine Drawing: 3.5-4 Liters

    Hi all I'm looking for gasoline engine drawing with a displacement of 3.5-4 liters. Any suggestions where I could find one? Oleg
  13. S

    Thermal Question -- Carnot Engine

    Homework Statement A Carnot engine extracts 745 J from a 592-K reservoir during each cycle and rejects 485J to a cool reservoir. It operates 16 cycles per second. Find work, efficient, temp of cool reservoir. Homework Equations W = Qh - Qc n=Wout/QhThe Attempt at a Solution I'm sure I can do...
  14. R

    Designing F1 Car w/ Duke 390 Engine: Sprocket Dimensions

    hello, I'm designng a f1 car,,, we are using a duke 390 engine...we are using a chain differential... now I'm trying to make the sprockets. to make this sprockets i need to know its dimensions.. that is sprocket teeth diameter width etc... so, I'm very much confussed with it. how to get this...
  15. O

    Internal combustion engine backpressure

    Hello everyone I got diesel engine, and there is a backpressure applied in the exhaust. I know that when the exhaust pressure reaches approximately 6 atm. the engine stalls. The question is, how I'm able to calculate this precisely, especially when the backpressure didn't reach it's maximum...
  16. A

    Thermodynamics (Entropy Generation and Heat Engine)

    Homework Statement A hot gas stream at 600K and 200 kPa is cooled at constant pressure to 300K in a pipe by direct thermal contact with the atmosphere. The mass flow rate of the stream is 0,1 kg/s and the atmospheric temperature and pressure are 300K and 100 kPa. Modeling the gas as an ideal...
  17. N

    Help with thermodynamics -- work of Carnot engine expansion

    Homework Statement I don't need help solving I just need some clarification. Since the carnot cycle is adiabatic, the first law would reduce to work= mass*(change in internal energy). On my test I was asked to calculate the work of the isentropic expansion of a carnot engine with air...
  18. S

    Brake Power, Engine Speed and bmep Relationship

    I'm currently doing a report on Petrol Engines and I'm having a problem with my results not making sense. Am I correct in saying Break mean effective pressure (bmep) should increase as Engine Speed (rev/min) increases? My results do not reflect this and I don't understand why. I have attached...
  19. C

    Basic thermodynamics, reversible engine process

    Homework Statement http://i.imgur.com/jmLqca9.jpg pic of question Homework Equations W = p x dV, Q = dU + W etc The Attempt at a Solution I know what the different stages are, a-b and c-d are isobaric, d-a and b-c are isochoric and I believe the answer to a, the net work done in one cycle...
  20. W

    LaTeX Info Request: "Latex Search Engine"?

    Hi All,' I remember there was a site where one could search using math symbols, like > , and Math terms. Anyone know what the name/address of that site is? Thanks.
  21. P

    Why is there a negative torque in TMD of 4 stroke engine?

    In the torque moment diagram of 4 stroke engine, there is a negative loop during suction stroke. Many books state that it is due to the higher atmospheric pressure. But, I do not understand the concept. Please help me understand why there is a negative and positive loop during suction and...
  22. M

    Connecting rod failure Hyundai Veloster 1.6

    I purchased this car new 2013, 29,999 miles and the dealer has been the only one who worked on it. We use synthic oil. After driving the last 100 mile at 60 mph the engine stopped. I had it towed to the dealership. The lower end of #4 con rod was sticking out of the Aluminum block. The...
  23. H

    This futuristic jet engine is very real

    http://www.cnn.com/videos/tech/2014/10/30/pkg-future-of-travel-jet-engine-leap-plane.cnn
  24. vetgirl1990

    Efficiency of a Carnot Engine

    The efficiency of a Carnot Engine is described by the relationship: Tc/Th = Qc/Qh, so that e(Carnot) = 1 - Tc/Th For heat engines, can their efficiency also be related to temperature as well? Or is the description of their efficiency just: e(heat engine) = W / Qh = 1 - Qc/Qh I am inclined to...
  25. siimplyabi

    How far does the train travel before the engine is ....

    Homework Statement .[/B] A model steam train engine has a mass of 2.3 kg is powered by a sterno and white gas mixture that heats a small boiler. Once sufficient steam pressure is produced, the train is released from rest. The train travels along a straight and level track. At any time after...
  26. I

    Engine torque: Can an alternator increase ICE torque?

    Hi there. What would happen if, while generating electricity with a fixed inlet power from the ICE, the alternator suddenly increase the out put demand by increasing the voltage? Does the engine would augment the torque while reducing RPMs? consider a self excited alternator, the voltage is...
  27. G

    Practical measurements of ramjet engine

    Hello everyone I am trying to design a ramjet engine. For that I need measurements of its parts. Does anyone know how to calculate them or have a link to a website where I could find more information?
  28. P

    Gear box design against specified engine specifications

    Dear all,i have recently been provided a task of designing a basic gear box for a vehicle having following engine specifications: 127cc, max torque: 7.8N-m Max. RPM: 3200 How do I proceed for this? Please guide me what all additional information is required for this calculation and what all do...
  29. E

    Automotive How does the throttle affect the RPM of an engine?

    Hello, I'm working on a car simulation and I'm attempting to implement a manual transmission simulation into the game. My question is, how do you find the rate of change of the engine's RPM when the gas pedal is pressed in the car?
  30. JasonHathaway

    Calculating Efficiency and Work in Otto Cycle Engine

    Homework Statement An Engine works within Otto cycle where the compression ratio is 6, and 350 kJ of heat was added to it. Determine the efficiency of the cycle and the work done if Cp/Cv is 1.45Homework Equations Efficiency Otto = (1- r1-k) Efficiency (eff.) =Work (W) /Heat Transferred (Q)The...
  31. T

    Cylinder Pressure of Combustion Engine

    hi, i want to ask about 4 time combustion engine torque. in my example we simulate a single cylinder gasoline 4 time engine which works 1000-4000 rpms and always have same fuel and air mixture in cylinder and so same burn pressure in each power time. these are the rules of question now i want...
  32. S

    Power output of automobile at different engine rpm

    I figure my 2.4 liter Volvo will burn about a liter of gasoline over an hour of idling (source: Natural Resources Canada). Since a liter of gasoline contains roughly 33.8 million joules (~9.4 kilowatt-hours) of energy, I figure that that means my car idles at a power output of around 9.4...
  33. A

    Straight engine vs flat engine on a 1 cyl. motorcycle

    Hello everybody I just got an old underbone bike, which I'm planning to build and finish before the end of this year. I found the engine to be quite pathetic (a 4 stroke, carburetted, 100 cc flat engine) so I'm going to do an engine swap with a more powerful but similar engine configuration...
  34. A

    Engine & Generator - Can Speed Increase Work?

    is it possible by increasing speed to 3000 rpm from 1500 rpm and reduce the hp half of engine that operates the alternator(for example in case 15hp engine reduce to 7.5hp for doing same work by doubling the rpm)?
  35. T

    Is there a limit on rocket engine exhaust velocity?

    I've been trying to figure this out for days. I'm told that atmospheric pressure imposes a limit on maximum possible exhaust velocity in the Earth's atmosphere, and that under STP conditions that limit is approximately 15,000 feet per second. But that doesn't make any sense. Suppose you had...
  36. rmoh13

    Is this a possible idea for an antimatter rocket engine?

    Antimatter can be contained in magnetic fields; what if we could somehow "propel" that magnetic field by using a magnetic nozzle when the small antimatter-matter reactions/annihilation occurs which produces thrust? This seems like a really stupid idea, but can you tell me some limitations about...
  37. M

    Does Conrod Length Affect Torque in Engines?

    Hi, Sorry if this is in the wrong thread I'm new to the forums. I was recently talking my mate about how engines produce power and torque and how there's so many factors in it. I mentioned the length of conrod would be a factor but my mate disagreed that it has no effect on torque. To my...
  38. SmritiB

    Gas Exhaust in 4 Stroke Engines: Continuous or Discrete?

    Is the gas coming out of the exhaust during the working of a 4 stroke engine continuous as long as the automobile moves? I know the intensity of air used depends on the speed, but the air that exhausts out, does it come continuously in time or like a discrete function ?
  39. J

    Rocket Specific Impulse vs Jet Engine Specific Impulse

    I really can't seem to wrap my head around why the specific impulse on a rocket is so much lower than that on a jet. I know a jet engine has a larger supply of oxygen, but I don't see why that has such a huge effect. I also know exhaust velocity plays a large part, but I would have thought that...
  40. Moteor

    Machinery Rated Power Calculation

    Hi everyone, Thanks for the help in advance. I have a project with a piece of machinery that is rated to 105 HP @ 540 RPM. I was wondering what the torque rating for the machine would be, whilst its being driven from a diesel engine? I believe there is a direct relationship between Torque and...
  41. Archenox

    Academic background for physics engine?

    Hello everyone! :smile: I am almost finishing a bachelors degree in computer science and I would like to have some insight on the possible academic backgrounds and career opportunities for someone who wants to be working with the creation and development of a physics engine. Considering that...
  42. anycast

    Calculate combustion engine torque

    Hi, I'm currently doing a small racing game where I allow players to tweak their car's engine (control number of cylinders, cylinder bore/stroke, turbo chargers, etc). I've understood the very basics of how combustion engines work but I'm still struggling on how to calculate engine torque...
  43. psvtrajan

    Electromagnetic Engine: Can It Power an Engine?

    Is there any engine which works using electromagnet?
  44. DHF

    Need help figuring out a possible fusion engine

    Hello, I am in the process of writing space based sci fi novella, I made a few posts last year and earlier this year regarding different aspects of the ship and crew. If anyone is interested, I wanted to concentrate on the fusion engine of the ship itself and hopefully come up with a feasible...
  45. D

    What engine supports air-friction with "push-back"?

    Hello Community! Hope I've finally found a forum which could help me with this question :) Currently I'm preparing for a rather big software project in college. For this, I need a 3D Physics Environment/engine which supports more or less realistic air friction. What I want to achieve is to...
  46. person_random_normal

    Exploring Alternatives to the Carnot Engine

    1 - T1/T2 gives efficiency of a carnot engine working between two temperature sources T1 &T2 and we know that, that efficiency is unbeatable but can there be another engine possible serving the same purpose as that of carnot engine working in an entirely different manner and MORE EFFICIENT than...
  47. Thom_Silva

    Is the energy output of an engine constant?

    I know that the power of an engine is equal to (rpm*torque)/ 9.54 (SI units). But does this mean that an engine when turned on is outputting the same amount of energy per unit time, every time ? . What happens when we press the gas pedal, does the power output increases? When i drive my car...
  48. Ketan Vadher

    How to calculate the max acceleration

    I have an engine with the following specifications: 305 cc, 4-stroke single-cylinder. Torque : 18.53 N m @ 2800 rpm. Weight of the car 275kg Coefficient of drag:1.15 Frontal area: 0.9177m^2 Rolling resistance:0.04482 Engine wheel efficiency: 78% How can i calculate the Max. acceleration and...
  49. HyperTechno

    Automotive Hybrid Cars with the engine as the generator

    We know that electric motors are very powerful(hp and torque) and efficient than all the combustion engines. There are lots of advantages of electric motors to be used to propel vehicles as you can have the same maximum torque at any speed, very high pickup, high top speed as well as no need of...
  50. CorvetteAB

    Want to set up a turbocharger for KTM 390 engine

    Hey friends, My college team takes part in college level racing events. They currently use a KTM 390 engine(race limit is 600). WIth the 20mm restrictor rule we can generate around 30-33hp after some tuning, after the restriction of course. Now we want more power. We need it. So we have 2...
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