Efficiency Definition and 950 Threads

I want to do a study comparation of PMSM and BLDC Motor. I want to analyze the cost efficiency if BLDC were subtitute to PMSM. Where should i start? what kind of data that i need?

Hi everyone, I’m Pavel! I’ve always been fascinated by space exploration and innovative engineering solutions. Lately, I’ve been working on some ideas to improve efficiency in space-related projects and would love to hear the thoughts of people with experience in this field. I’m here to learn...

The subject of self-studying has been discussed extensively. However, one part that I find missing is an efficient workflow. I have 24 hours a day but I can only manage to study 4 hours a day (i.e., reading, understanding, taking notes, and doing problems). I have done this for months but I...

I make this 60km trip every week or two and I've always been obsessed with tracking distance. time and velocity on trips. [ digression ] This is a graph I drew up of a different trip, years ago: This was long before Waze and Google Maps. I had a scrap of paper on my steering wheel and wrote...

The use of interference principles in quantum mechanics to convert solar energy into electrical energy can be represented through the concept of quantum dots, or nanoparticles, which have properties that contribute to enhancing the absorption of light and generating the photoelectric effect...

I read an interesting article on progress in making transmission lines more efficient: https://reneweconomy.com.au/super-cheap-transmission-upgrades-could-double-capacity-and-open-floodgates-for-renewables/ While, of course, we do not discuss politics here, this new technology has many...

I’m looking at designing a portable propane electric generator that’s light for camping ect’ What ideas on how to improve the efficiency on the alternator and the inverter from dc to could I improve upon or incorporate? Thanks Rosd

Hello everyone, I would like to ask some questions regarding my thesis. I have a problem identifying which load I should use to calculate the power output of the small generator. I use an Archimedes screw turbine as the prime mover of my generator, and the water flow is low in my locality...

Hello, I have been reading that a coal power plant and a nuclear power plant have similar efficiencies, i.e. ~30%. This 30% refers to the conversion of thermal energy into electricity. For example, for 100 Joule of thermal energy, we only get 30 Joule out of electrical energy. How is that...

Hello guys, I did a efficiency analysis with two different propellers. For that I build up an experiment to make measurements. The experiment is build up like this: You can see a prop inside the tube which after turning on will pump water from one side to the other. After a certain duration...

So far this is what I have: I have the power source, two triple in a battery case, negative to the T emitter, T output to the (-) of motor, T base through a resistor to the switch, switch to the (+) of motor. I tried wiring the Led to this junction and the switch, but either the motor or the...

Please see the attempt sketch. Basically I have four very inefficient DC motors all commonly turning a single drive shaft at the center of the system. Currently these motors that are 2.47% efficient individually able to produce 5 newton meters of torque at 28 RPMs. So my question is this. If I...

Please see the attached sketch. Basically I have a system of three gear boxes, each with their own respective efficiencies. I'm trying to determine, at the end of this string of gearboxes, what the overall efficiency is. How might one go about determining this? Do you just take the average? 70 +...

Hello, Does anyone know typical values of cutoff ratio in diesel engines? And how have they evolved through time? Thank you!

I made a presentation where I derived, or at least attempted to derive, the formulae for the upper bounds of the efficiency/cop (cop = coefficient of performance) for a heat engine, work driven heat pump, and a heat driven heat pump with 3 thermal reservoirs, hot, warm, and cold. There are many...

I didn't have much trouble with part a but I'm struggling with b,c, and d. I considered the efficiency formula for a heat engine e = work done by engine/ qh but i am unsure of how to approach it. for part c) not sure how i can get to Tc without knowing Th for d) my gut is telling me 5/2 but i...

Hi I want to know the power efficiency of linear piezo electric motors in percentile.

This was my first attempt which was not right. But it was at least a percent unlike my 2nd attempt. This was my second which I found on another forum website. It said it found the work of step 1, heat absorbed of step 2, work of step 3, and absorbed heat of step 4. However, the answers to the...

TL;DR Summary: Just need help with verification of data submitte 1 of 94 Efficiency distance over 3000 km +, plus Temperature over that distance 1-inch amorphous magnetic core 0.05 microns graphene 0.10 microns metallic PZT Helical copper wire with 15 mm...

Really perplexed me as the answer provided does not solve for mass ... seemingly wants to use mass as a unit of height? Or perhaps I'm off base ... really just curious if this is even correct or possible? Thanks in advance

What approximate portion of generated heat from being active on the treadmill, both the person on it as well as the machines themselves would be compensated/cooled if the treadmill resistances would be disabled/removed and instead 1/2 end cylinders would be connected to an air conditioner...

How would you calculate the fuel efficiency of a rocket (around 10 tonnes) going near the speed of light?

Hello All I've conducted an experiment to work out the efficiency of a small motor, and it comes out to be very low. Have I done my calculations correctly? I connected the motor to a gearbox (made from Meccano) and a winch and used it to lift a weight. I measured the DC voltage across the...

Hello, I am trying to solve a problem about an open Gas Turbine. The given information would be: - An open gas turbine draws in air from the surroundings having the m, cp, T1 and constant kL with the next values: , - The air flow is heat over natural gas supplied: - The pressure ratio is 𝜋...

Hello, I'm confused between the difference between the thermal and mechanical efficiency of a Sterling heat engines or heat engines in general. I hope you could be able to guide and help me. Thank you

Consider mixing ice water with the hot water and vice versa so that the two reservoirs are closer to the same temperature. What will happen to the mechanical/thermodynamic efficiency and ideal Carnot efficiency of a heat engine?

Hello forum, I am reading this article on quantum machine learning. At one point in the article (page 7) they plot the ROC curve as background rejection vs. signal efficiency. Researching these concepts (since I did not understand them fully), I read that ROC curves should be plotted as TPR...

My book states the answer to this problem is . I have gotten very close to the answer. My problem is my Tc/th and tc/tm are flipped compared to the solution. I feel like I am missing something in my algebra but can't see where I am going wrong. Could I get some help identifying where my...

I have tried to solve a problem about the amount of watts a motor needs to recive if i want an elevator of 1250Kg to move at a speed of 2m/s +/- 0,10m/s after 3 seconds. The motor has an efficiency of 0,80. I've tried looking at my teachers uni recording, but it doesn't seem to explain this part...

How efficient are solar panels? How can their efficiency improve? Besides their benefits, what are the ecological impacts of solar energy?

Here is a diagram of my interpretation of the problem: Where I'm thinking that the engine originally takes heat from ##T_h## to ##T_l##, in which case ## \frac { Q_{h} } { T_{h} } = \frac { Q_{l} } { T_{l} } ## and ## W_{out} = Q_{in} - Q_{out} = Q_h \left( 1 - \frac {T_l} {T_h} \right) ##...

If I orient my refrigerator such that the condenser coils at the back are facing a glass door (least insulation in room, cold outdoors) will CP increase? CP=Qc/(Qh-Qc) so Qh-Qc will be smaller thus CP larger. Could this damage refrigerator?

We all know about various kinds of market available blowers and their efficiency is well known more or less. I recently came to know about dyson fan/air multiplier I want to know which one, whether market available blowers or the Dyson fan is efficient in terms of creating mass flow rate at...

At the end of the measurement I made with a detector, I only have the energy and count values as in the attached excel file. How can I find the peak values with the data I have and calculate the efficiency?

I used a HE (high efficiency) washer for the first time today at a relative's house (they're gone on vacation, so no one "warned" me). I washed a "medium" load of clothes ("medium" for a traditional/regular washer) and to my utter shock, the water level was only about 1/5 or 1/4 (at most) of...

Through an intriguing fictitious dialog between Sadi Carnot and Robert Sterling, Prof. Israel Urieli of the Ohio University shows that it is not required to invoke entropy, the second law of thermodynamics, and the Carnot cycle with the [ideal] adiabatic processes in order to find out the...

So I am doing an experiement about DC motors, and I would like to know why the efficiency plot looks like a parabola. What is the structure behind that. Thank you in advance

Currently my task is to count number of iterations of golden section search verus interval bisection search of a function y = x^2. Golden section search took about twice the number of iterations than interval bisection search. If I lowered the golden ratio from 0.618 to 0.5562 , the number...

I have been trying to convince someone that it is wrong to compare the death percentages of two different populations (percentage of death of Covid-19 cases per category: vaccinated vs unvaccinated) in an uncontrolled setting (i.e. real-world data), and conclude that the Covid-19 vaccine does...

I want to create an LC circuit with varying inductors and compare those inductors for efficiency. Would it be accurate to suggest measuring the area under the curve of the first cycle of the resonant frequency would determine which of the inductors are most efficient? If the area is greater...

Why are beta voltaic cells so inefficient? Is it because the incident electrons are incredibly fast? According to a research, the incident electrons that get absorbed by the voltaic material are so fast that most of their energy is wasted as phonon and sonic energy. If we substantially slow down...

Hi, i have this question and don't understand it. can somebody explain what i have to do. i know a ideal engine is a engine running on carnot cycle i what the cycles are i don't know what relative efficiency is and what there looking for (Q) Review the relative efficiency of ideal heat engines...

hello, I did the simulation for the voltage multiplier in Vspace and I want to calculate the efficiency but the OUTPUT POWER is always negative. Do I need help? can I calculate the power losses of this sextupler voltage multiplier or it is very complicate to calculate it ?

Evaluate 2-stroke & 4-stroke Diesel engines performance in terms of thermal & mechanical effiniecy HAs anybody got any links. all i can find is for petrol (2-stroke and 4-stroke). Is what i got so far any good?Thermal In a 2-stroke power stroke compared to a 4-stroke power stroke thermal...

I don't have an idea of where to start. I tried to do Ein = 1/2 mv^2 ------ (1/2)(1)(10)^2 ----------- 50 but i don't know where to go from here

The answer in the textbook says 0J but I am not sure what the concept behind it is. Does it have something to do with gravity?

I don't know English well, translated using google translate. The working mixture ignites at TDC, and at this point the crankshaft looks up (0 degrees). As the piston descends, the force that the piston needs to travel a certain distance (for example, 1 mm) decreases, up to the moment when the...

For electrochemical energy devices such as batteries or fuel cells working reversibly, efficiency is defined as: η=ΔrG⦵/ΔrH⦵ Since cell operates reversibly Gibbs energy change of the system is equal to electrical work done by the cell, so we can instead just use standard Gibbs energy of...

I have tried looking up online with the photoelectric effect, it just mentioned the energy of the photon must have to equal to band-gap energy. Yet, it didn't mention if 100% can be reached in that case, or if a single bandgap makes any effect...