MP-AI-20/mechanical-engineering-skills - Page 16

transient-conduction

Transient heat conduction — lumped capacitance, Biot number, Heisler charts, semi-infinite solid, 1D Fourier series solution, product solution for multi-D problems.

tribological-coatings

Tribological coatings — PVD (TiN, TiAlN, DLC), CVD, thermal spray, friction coefficients, hardness, adhesion, applications in cutting tools, bearings, forming dies.

tribological-testing

Tribological testing — pin-on-disk (ASTM G99), block-on-ring (G77), four-ball (G99/D2266), linear reciprocating (G133), ball-on-flat, fretting, dry sand/rubber wheel (G65), high-speed high-stress abrasion (G105), friction coefficient measurement, wear rate…

tribology

Tribology — lubrication regimes (Stribeck curve), hydrodynamic bearing theory (Reynolds equation), EHD lubrication, film thickness, wear models (Archard), friction, lubricant viscosity selection.

truss-analysis

Truss analysis — method of joints, method of sections, zero-force members, statically determinate/indeterminate trusses, space trusses, deflection by virtual work/unit load method.

tuned-mass-damper

Tuned mass damper (TMD) — Den Hartog optimal tuning (f_opt = 1/(1+µ), ζ_opt = √(3µ/(8(1+µ)³))), mass ratio µ, frequency response with TMD, stroke limits, multi-degree TMD (MTMD), pendulum TMD, active and semi-active TMD (MR damper), TMD for wind-induced…

turbocharger-design

Turbocharger design — compressor/turbine matching, surge margin, efficiency islands, boost pressure, wastegate, intercooler, twin-scroll, electric turbo, SAE sizing.

turbofan-cycle

Turbofan engine thermodynamic cycle — bypass ratio (BPR), overall pressure ratio (OPR), turbine inlet temperature (TIT/T4), fan pressure ratio (FPR), specific thrust, thrust specific fuel consumption (TSFC), cycle analysis (ideal and real with component…

turbomachinery

Turbomachinery — Euler turbine equation, velocity triangles, centrifugal compressors, axial turbines/compressors, specific speed, cavitation, pump selection, turbine efficiency.

turning-operations

Turning (lathe) operations — cutting speed, feed, depth of cut, tool life (Taylor), cutting forces (Merchant/Oxley), surface roughness, insert grades, power, MRR.

two-phase-flow

Two-phase gas-liquid flow — flow regimes, void fraction, Lockhart-Martinelli pressure drop, Baker chart, two-phase multiplier, steam-water quality, drift-flux model.

ultrasonic-welding

Ultrasonic welding — energy director design, joint types, frequency (20-40 kHz), amplitude, weld force, energy/time/distance modes, thermoplastic selection, amorphous vs. semi-crystalline, AWS/AWS standards.

underground-piping

Underground piping systems — soil load (Marston formula for buried pipe), live load (AASHTO H20 truck), pipe bedding classes and load factors, flexible pipe deflection (Iowa formula Δx/D), rigid pipe (concrete, clay) crack load and three-edge bearing…

underwater-acoustics

Underwater acoustics — sound propagation in seawater (speed, absorption, spreading loss), sonar equation (SL-TL-NL+DI≥DT), passive and active sonar, transmission loss (spherical/cylindrical/ray tracing), transducer design (piezoelectric, BVD model,…

unit-converter

Mechanical engineering unit conversion — stress, force, pressure, length, area, moment of inertia, torque, power, temperature, thermal properties, flow rate, viscosity. Imperial ↔ SI ↔ metric.

value-engineering

Value engineering (VE) — function analysis (FAST diagram, primary/secondary/basic functions), value index V = F/C, 40 inventive principles (TRIZ), job plan phases (information, function analysis, creative, evaluation, development, presentation), Pareto…

valve-cavitation

Valve cavitation — cavitation inception (σ = (p1-pv)/(p1-p2)), choked flow, flashing, incipient cavitation coefficient σi and critical cavitation coefficient σc, damage potential index (cavitation index Cv), control valve sizing with FLp correction,…

valve-field-issues

Valve field troubleshooting — gate galling (adhesive wear, Stellite hardfacing), pressure lockup (thermal expansion ΔP=βΔT/κ_T, DBB cavity), wire drawing erosion, cavitation (σ=P2-Pv/P1-P2), flashing, fugitive emissions (API 624, ISO 15848), seat leakage…

valve-noise

Control valve noise — aerodynamic noise from gas/steam throttling (IEC 60534-8-3 method), mechanical vibration, hydrodynamic noise from liquid cavitation, sound power level Lw calculation, pipe wall transmission loss TL, A-weighted sound pressure level at 1m…

valve-sizing

Control valve sizing — Cv/Kv calculation for liquid (ISA/IEC 60534), gas (compressible, critical flow), steam (superheat/saturated), inherent flow characteristics (equal percentage, linear, quick opening), installed characteristics, rangeability, valve…

valve-train

Engine valve train — cam profile design (harmonic, polynomial, spline cams), valve lift and timing (IVO/IVC/EVO/EVC, duration, overlap), cam follower dynamics (contact stress, follower acceleration), rocker arm geometry and mechanical advantage, valve spring…

vehicle-aerodynamics

Vehicle aerodynamics — aerodynamic drag (Cd and frontal area A, drag force F_D = 0.5ρCdAv²), lift and downforce (Cl, Cl_f/Cl_r), road load equation, cooling drag, underbody aerodynamics (diffuser, flat floor), active aerodynamics (active rear wing, air…

vehicle-dynamics

Vehicle dynamics — handling, tire forces, bicycle model, oversteer/understeer, roll stiffness, pitch/bounce, load transfer, stability derivatives, braking performance.

verification-validation

Verification and Validation (V&V) — ASME V&V 10/20, model validation metrics, uncertainty quantification, code verification (Richardson extrapolation, MMS), validation hierarchy, AIAA standards.

vibration-absorber

Vibration absorber and tuned mass damper — undamped/damped DVA design, optimal tuning (Den Hartog), frequency ratio, mass ratio, suppression bandwidth, applications.

vibration-acceptance-criteria

Vibration acceptance criteria — ISO 10816/20816 machinery severity zones, velocity RMS limits, bearing acceleration envelope, process plant piping vibration (Energy Institute), hand-arm vibration HAV.

vibration-isolation

Vibration isolation design — transmissibility, mount stiffness selection, damping optimization, active vs passive isolation, multi-axis isolation, machinery mounting, seismic isolation.

vibration-testing

Vibration testing — accelerometers, modal testing (EMA/OMA), frequency response functions (FRF), coherence, impact hammer, shaker setup, ODS, data acquisition, resonance identification.

visual-inspection

Visual inspection (VT) — direct and remote visual inspection (RVI), borescope types (rigid/flexible/videoscope), resolution and illumination requirements (ASME V Article 9), minimum detectable defect size calculation, illumination ≥ 500 lux (direct) / ≥ 50…

volute-design

Pump/fan volute design — spiral volute geometry, constant velocity vs. constant angular momentum methods, diffuser design, radial force, throat area, scroll design, double volute.

von-mises

Von Mises yield criterion — principal stress transformation, 2D/3D von Mises stress, Mohr's circle, distortion energy theory, comparison with Tresca, failure envelope.

water-hammer

Water hammer (hydraulic transients) — Joukowsky equation, wave speed, pressure surge, valve closure time, pipeline protection (surge tank, PRV, air vessel), Allievi equations.

waterjet-cutting

Waterjet cutting — pure waterjet (PW) and abrasive waterjet (AWJ) processes, Bernoulli orifice jet velocity, kerf width and taper, cutting speed models (Hashish, Zeng), standoff distance, abrasive type and grit size, nozzle wear, cutting depth for multi-pass,…

wave-energy

Wave energy conversion — ocean wave power density (P = ρg²H²T/(32π)), point absorber (Froude-Krylov force, heave resonance, power take-off PTO), oscillating wave surge converter (OWSC), attenuator (Pelamis), oscillating water column (OWC, Wells turbine),…

wave-spring

Wave spring design — flat wire, multi-turn, Smalley wave springs, load-deflection, space-saving vs coil spring, material selection, applications.

weibull-analysis

Weibull analysis — 2-parameter and 3-parameter Weibull, Weibull plotting, maximum likelihood estimation, B10/B50 life, confidence bounds, bathtub curve, reliability prediction.

weld-analysis

Weld design and analysis — fillet and groove welds, weld groups under combined loading, AWS/AISC allowable stresses, throat area, fatigue of welds, preheat requirements.

weld-process

Welding process selection — SMAW, GMAW, GTAW, FCAW, SAW, resistance welding, laser. Heat input, distortion control, preheat, PWHT, inspection methods, AWS D1.1 qualification.

welding-field-issues

Welding field troubleshooting — porosity (gas entrapment, hydrogen, nitrogen), hot cracking (solidification/liquation cracking, Varestraint test, carbon equivalent CE), cold cracking/hydrogen-induced cracking (HIC, Pcm formula, preheat calculation, CEIIW),…

welding-metallurgy

Welding metallurgy — HAZ zones, grain growth, solidification, weld microstructure, martensite formation, carbon equivalent, PWHT, hydrogen cracking, preheat, interpass temperature.