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Questions tagged [turbines]

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How do i choose the most optimal turbine (Style, pitch, size...) for a very small scale Hydropower project?

I have a project in which I am designing a lightweight, portable hydropower system, and I'm unsure of how exactly I am to choose the correct style of turbine. For context, the turbine is only really ...
Eoi McTaggart's user avatar
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1 answer
33 views

When something undergoes angular acceleration (like a bar) how does the distribution of forces look along the bar?

This is something kind of explained with propellers and turbine blades but I'd love some good explanations. Thank you!
Mechs_and_Specs's user avatar
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1 answer
153 views

Which would be the more efficient design for a 10 kW micro steam turbine - axial or radial?

I'm aware of the inefficiencies of down scaling turbines due to boundary layer proportions to the laminar flow, but if say you'd have to design a 10 kW steam turbine, what would be the best design? ...
Riccardo's user avatar
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1 answer
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Can a scroll compressor be used to generate power?

Scroll compressors are efficient, reliable, and a fill a pressure/flow niche in the array of available compressor technologies. However, I have never seen one used the other direction for generating ...
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Why does flow capacity of axial turbine decreases with increasing RMP?

when studying the compressor map and the turbine map of a gas turbine, I noticed that the flow capacity of the compressor increases with speed increase (RPM) and the flow capacity of the turbine ...
GRANZER's user avatar
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How does resistivity affect the susceptibility of a steel alloy to induction heating?

For context, my question is related to the use of heating to elongate studs for casing tightening and loosening. In turbine casing assembly, in addition to torquing the nuts, studs have holes drilled ...
George's user avatar
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1 vote
1 answer
141 views

What is the efficiency of Solar energy run turbines? Are they better or worse than Solar PV cells?

The Solar PV cell has an efficiency of 25-40%. Now steam turbines run by coal or some other fuel have an efficiency of approximately 60-80% What is the efficiency of steam turbines run by Solar energy?...
Hari Kumar's user avatar
1 vote
1 answer
30 views

Is there a way to 'switch OR engage/disengage' power between two different rotating shafts depending on a set RPM (wind speed)?

I'm a final year mechanical eng student, I'm working on designing a prototype of a 'Hybrid vertical axis wind turbine (VAWT)". This hybrid turbine consists of two types of VAWTs Savonius & ...
Yashwanth SriHari's user avatar
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1 answer
76 views

Acceptability of gaps between rotor blades of a gas turbine

While designining the geometry of different sections of the turbine blade, I've noticed that some of the sections (closer to and including the root) do not have visible gaps if viewed from the leading ...
Astrowolf_13's user avatar
0 votes
3 answers
62 views

Would injecting water in a turboshaft engine avoid turbine material meltdown?

For the little I know about turbine engines, I know that these run at enormous high temperatures and thus, need nickel based superalloys. From what I know, jet engines use a smart use of air flow ...
Fulano's user avatar
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Would a modern mercury vapor / steam combined rankine cycle be more efficient than a steam only cycle?

During the first half of the 20th century mercury vapor turbines were in use in commercial power stations. The mercury vapor was the working fluid for a high temperature Rankine cycle and the mercury ...
JanKanis's user avatar
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140 views

What is the ramp rate (up and down) of the Siemens SGT-800 gas turbine (62MW variant)?

I can't seem to find the ramp rate of the Siemens SGT-800 gas turbine in any of their brochures or data sheets. Looking specifically for the ramp rate of the Siemens 62MW SGT-800 gas turbine (in ...
M.Calugaru's user avatar
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0 answers
41 views

What drives the mass flow rate in axial turbofan between the compressor and the turbine when compressor is fully choked?

I haven't found the answer in the forum or elsewhere, but maybe I have searched badly, in which case please forgive me in advance. For a steady nominal operation of a turbofan, I have heard that the ...
Jonses's user avatar
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1 answer
35 views

Would it be possible to harness the energy flow from a continuous water system?

I’m working on a project to put Archimedes screw turbines into drains and sewerage water. However, as an experimental project I wanted to test out an idea to evaluating turbine degrees and flow rate ...
Suzie's user avatar
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1 vote
1 answer
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Is standard airfoil theory suitable to VAWT blades?

Let me preface this by saying that I did my research and have r̶e̶a̶d̶ skimmed a lot of papers on new blade profiles for vertical-axis wind turbines (VAWTs). What I have yet to read about is a blade ...
fho's user avatar
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1 answer
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Is there a type of rotary positive displacement pump that can pump hot exhaust gases?

Is there a type of rotary positive displacement pump that can pump hot exhaust gases (~900°C), that is, not requiring lubrication that would otherwise be burnt off?
Francis L.'s user avatar
2 votes
1 answer
85 views

Fluid dynamics - Velocity required to turn wheel

I want to calculate the velocity of a fluid required to turn a water wheel at a specific angular velocity. The fluid enters the housing of the water wheel through a inlet channel. It turns the wheel ...
loStraniero's user avatar
3 votes
3 answers
254 views

Why not build a wind turbine like a vertical Kaplan turbine?

Vertical Kaplan turbines are often used for hydropower plants. They can have an efficiency of more than 90%. Why don't we see similar designs for wind power? I mean one could imagine to redirect wind ...
asmaier's user avatar
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1 vote
2 answers
213 views

Expected power increase when replacing old (>20 years) wind turbines [closed]

Plenty of onshore windfarms around the world are reaching the 20-25 year old mark and thus may be on the process of repowering. Let's say an old wind farm has 10 rotors of 0.5 MW each (total power <...
Brenlla's user avatar
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2 answers
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Doubt on a shaft-turbine-generator system

Consider a shaft which connects a turbine to a generator. Initially, none of the parts are moving. Now the turbine starts to rotate and the torques act on the shaft from both the turbine and generator ...
Harshit Rajput's user avatar
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3 answers
126 views

Confused about how combustor pressure is lower than compressor exit pressure in turbomachinery?

I understand the compressor exit pressure is the highest pressure in all of the turbomachinery, and the combustor is a constant pressure process, and since the combustor P is lower than compressor ...
kaz's user avatar
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0 answers
214 views

Theoretical calculation of blade pitch angle

I would like to start by apologizing for my ignorance, I am sure I am missing something very obvious here. I am using data for the NREL 5MW reference turbine, and specifically power curve and power ...
Infinity77's user avatar
-1 votes
2 answers
111 views

Could the St. Louis Gateway Arch be used as a support structure for a giant vertical axis wind turbine?

I am curious to know if the St. Louis Gateway Arch would be strong enough to act as a support structure for a giant vertical axis wind turbine. I way I am envisioning this being constructed is that a ...
user57467's user avatar
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2 answers
88 views

Is transmitting windmills' mechanical power to ground level that complex?

Thinking about the complications of building and maintaining turbine rooms installed at high altitudes in horizontal axis wind turbines (plus the difficulties related to it when, for example, a fire ...
Andrestand's user avatar
1 vote
1 answer
691 views

Angular Velocity And Flow Rate Relationship Of Turbine

I was designing a turbine to be utilized in order to measure the flow rate of a river system. I can measure the angular velocity of the shaft by utilizing a magnet and hall sensor, however, in order ...
Amit 's user avatar
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1 answer
124 views

I want to determine the flow rate and required turbine size for an offshore hydroelectric scheme and need help

I'm creating a report on the possible implementation of a sub hydro system and need some help. I've attached the image of what I'm proposing, where I've essentially created a head via a riser B with a ...
Kuriosity's user avatar
1 vote
1 answer
36 views

Weibull distribution Units - ENGIEQSOL

I am using Engineering Equation Solver, and it has been telling me the units of my distribution are inconsistent. According to a the book I am reading, I think it should be unitless (as it is a ...
RMS's user avatar
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1 answer
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What does the author mean? Turbomachinery - Reaction

I am reading a book of Fundamental Energy Systems. The author describes the rate of change in head for a turbomachine as: $$ \frac{1}{2}[(V_1^2-V_2^2)+(U_1^2-U_2^2)+(V_{R2}^2-V_{R1}^2)] = H =U_1V_{u1} ...
RMS's user avatar
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0 votes
3 answers
165 views

Correct wind Weibull distribution for wind+solar system

I'm trying to forecast the peak power output for a wind + solar system. The solar output as a function of time of day and month can be forecasted easily. I also have the historical wind speed for a ...
hurreechunder's user avatar
1 vote
2 answers
79 views

Hydraulic energy recovery for high-pressure, low flow (non-steady state) conditions

What would be the best way to implement hydraulic energy recovery while de-pressurizing a pressurized volume of silicone oil initially at 1500 bar. Can a piston pump be concievably repurposed as a ...
I. Lango's user avatar
0 votes
1 answer
97 views

How to do Blade Element Momentum Theory Analysis for NACA airfoils?

I wanna perform BEMT analysis on blades of different geometry and not just symmetric thin airfoil. How to do this?
Adithya NYY's user avatar
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0 answers
19 views

Blade efficiency of a franscis turbine

The blade efficiency of a turbine is defined as the ratio of the power extracted from the fluid by the rotor to the power available at the inlet of the rotor. The power available at the inlet of the ...
Ganish Ananth A M's user avatar
1 vote
3 answers
93 views

Practicality of energy recovery from HVAC systems?

I've been thinking about ways to maximize efficiency in large buildings, and one thing I thought of was to place some sort of turbine in the exhuast vents or smokestacks of factories, power plants, ...
MD88Fan's user avatar
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-1 votes
1 answer
368 views

Can a steam turbine can be used with compressed air?

Suppose that a generator is connected to the turbine. I have a large amount of compressed air which will be acting as the driving force for the turbine. For the above case will I be only left with the ...
Tank's user avatar
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3 votes
0 answers
940 views

Why funnelling air in order to increase the velocity is a bad idea when generating power

Disclaimer: I’m not trying to violate the conservation of energy here; I know that’s impossible for us mortals. I think I’m either wrong or not considering something, I just want someone to point it ...
David Nolan's user avatar
2 votes
1 answer
268 views

How should one clean the blades of a turbomolecular pump

I have a turbomolecular pump from Osaka vacuum that is quite dirty, and I'd like to clean the blades off to improve balance. I'm not quite sure how to approach this, I've tried carbon cleaner for ...
tuskiomi's user avatar
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2 votes
0 answers
223 views

what is the difference between jblade, qblade, and xflr5 softwares?

I am working on a propeller design, and I've came through Jblade which helped me in the airfoil design, yet as I can remember, xflr5 can also do this... doing some internet search, i found that Jblade ...
Ibrahim Jaafar's user avatar
-1 votes
1 answer
248 views

Accounting for pressure energy in Euler turbine/pump equation

For all the analysis to find work done by a compressor or work done on a turbine, the book I'm reading (Fundamentals of Turbomachinery by Venkanna B.K) uses the Euler turbine and pump equation, $$W=\...
Skawang's user avatar
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1 vote
2 answers
106 views

What is the purpose of combustor in a gas turbine

I have read online that a gas turbine converts the chemical energy in the fuel gas to mechanical energy of the turbine blades. The way I see it, because of this hot air one would have to go for heat ...
user110565's user avatar
1 vote
0 answers
85 views

How many kWh this turbine would generate?

My grandfather and I are running some experiments down the river, however we don't have expertise in engineering so I bring up this question to the community and hope someone could help. How many kWh ...
Simple's user avatar
  • 111
1 vote
3 answers
208 views

Some questions about the specific speed (Ns) of hydro turbines

So we all know the basics behind specific speed Ns of hydro-turbines. $$N_s = RPM \cdot \frac{ \sqrt{(P)} }{ H^{1.25}}$$ where P is the power output and H is the head. The theory is that once you ...
sithvincent's user avatar
-1 votes
2 answers
145 views

What is and how do you calculate the wind velocity design for wind turbines?

I am finding it difficult to get consensus on the definition of design wind speed for aeolic turbines. I thought it was the velocity that corresponds to the maximum power output, but I have already ...
Vitor Aguiar's user avatar
0 votes
0 answers
110 views

Most efficient turbine for harnessing energy from bidirectional air flow?

I am currently working on designing an oscillating water column as part of a project. In summary: OWC are devices with a semi-submerged chamber or hollow open to the sea below, keeping a trapped ...
user73910's user avatar
  • 101
2 votes
2 answers
1k views

Why don't we use hot water instead of steam to drive the turbines?

I guess if we do this then, the size of the turbines could become smaller. The condensor's size also might be reduced. But the catch over here is the energy density of hot water is less then that of ...
Mohammed Adain's user avatar
0 votes
1 answer
590 views

How to calculate airflow in m3/min on a gas turbine outlet?

I'm currently trying to figure out the airflow of a gas turbine in m3/min. I thought that i would be able to measure the windspeed over a known cross section on the intakte of the turbine and then ...
Claudi's user avatar
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0 votes
0 answers
22 views

Are there impulse turbines operating on hot exhaust gas?

Are there impulse turbines that operate efficiently on hot exhaust gases rather than water as the working fluid? Im thinking about something analogous to a water wheel, since it seems that bucket/...
Francis L.'s user avatar
0 votes
0 answers
30 views

What exactly makes reaction turbines work?

I was reading about reaction turbines on Wikipedia, it says: "Reaction turbines develop torque by reacting to the gas or fluid's pressure or mass. The pressure of the gas or fluid changes as it passes ...
Kv07's user avatar
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0 answers
167 views

Can someone please give me a hint on how to draw velocity triangles for this specific inward flow reaction turbine problem?

I'm trying to calculate the hydraulic efficiency for this turbine by using the formula: E(hyd) = (VwU)/gH where Vw= Velocity of whirl at inlet, U=velocity of runner at inlet, H=Given Head, and g=...
Hamza's user avatar
  • 11
3 votes
2 answers
485 views

Do 3 blade wind turbines generate more power than a 9 blade, all else being equal?

After doing some research, I have come to the realization that 3 blade design horizontal turbines have the greatest maximum coefficient of performance. Most sources seem to agree a Cp of ~0.45 at TSR=...
David_M16's user avatar
2 votes
1 answer
183 views

In horizontal axis wind turbines, why does axial component of absolute velocity stay constant (wake rotation theory)

I am having hard time understanding how does the axial component stay constant through the rotor. Every resource i look just says it is due to mass conservation but never gives the actual conservation ...
redginer's user avatar