Request someone categorize low and high cycle fatigue in turbine engines. For example, what causes (or how do you get) high cycle fatigue vs. low cycle fatigue. I'm thinking in terms of vibration and gag cycles, etc.
Can someone describe how you determine the installation losses (i.e., due to inlet, exhaust, power extraction, etc.) via flight testing for helicopters. What data do you collect and then what calculations are performed on the data to determine the specific and bulk installation losses.
Thanks...
Can someone please provide a basic explanation of a turbine engine surge and stall. The specific application is for Rotorcraft (Turbo-Shaft Engines. What are the specific differences between and surge and stall? What causes them? How do you prevent them? Does this happen only in the...
I am trying to understand engine controls (gain and phase margin) as it relates to rotorcraft engine airframe compatability. Can anyone recommend a basic easy to read resource for this (i.e., engine controls for dummies).
How do you test a helicopter to determine if it meets a performance requirement (i.e., 4k/95). What does this mean in terms of altitude and temperature. It surely will not be 95 deg. F at 4,000 ft. pressure altitude. Can someone explain how you test for this requirement?
Can someone please provide a simple explanation of the function of the helicopter turbine engine controls including what basically it does and how it interfaces with manual inputs from the collective and cyclic.
Also, any simple books/references on this subject?
Can someone please provide a simple explanation of torsional instabilities and how it relates to the operation of helicopters. I have also heard of helicopter related torsional instabilities associated with engine power demands. Please comment.
Also, any good web sites and or basic books that...
Can someone please provide a simple explanation of a helicopter transmission split torque design including how it contrasts existing transmission designs where you have 2 input pinions (one connected to each engine). Any good references (web sites) on this issue would also be appreciated.
I have a component that has machining chatter on the threads. The threads take a locknut which has a torque of 1,000 in-lb. The material is a 1050 temper PH hardening stainless steel. The threads are acceptable via "go", "no-go" gaging. Is there a typical criteria or methodology for...
We have approximately 400 parts that were manufactured but not embrittlement baked subsequent to nital etch (in accordance with the drawing/specification requirements). The drawing requires that the parts be baked within 8 hours after nital etch. Consensus is the material grain boundaries may...
I'm trying to determine the practical thickness limitation of electroless nickel. The base material is 9310 steel. Various literature states that e-nickel can be plated up to .010" thick, however, I am working with a couple of vendors (including a plating house) that states the maximum...
Is there any heat treat hardening process (i.e., specific times, temperatures, etc.) for 440C stainless steel that will minimize the presence of carbides and make sure the carbides are finely dispersed within the matrix and not distributed along the grain boundaries.
Manufacturing processes such as chrome plating can have an adverse effect on both fatigue life and fatigue strength. Let's say you make the following statements:
1. The process may reduce the fatigue life of a component by 50%.
2. The process may reduce the fatigue strength of a component...
Can someone please describe what a gear hunting tooth is and also:
1. How does it effect the operation of the gear (i.e. wear, loading)?
2. How can you tell by the drawing if a gear has a hunting tooth (i.e. ratio with mating gear, etc.).
3. Any additional information on this subject would...
How are helicopter gearboxes (i.e., main transmissions, tailrotor gearboxes, etc.) typically rated (i.e. Horsepower, Torque, etc.)? Please explain. I know they can vary, however, what is a typical rating for systems currently fielded.
It's my understanding chrome plating reduces the fatigue properties of the plated substrate. Typically by how much (%)? What causes the reduction? Is the reduction for electroless nickel plating as much as hard chrome plating? If available, please provide data.
