What is Professor Kirby Bot

AskProfessorKirby.com is meant to be a forum where people can ask fluid mechanics questions and I answer them, or Professor Kirby Bot answers them, or both. Most people ask questions of PK Bot, because it answers faster. I answer questions in the "No Robots" category, but I am often slow.

I work at Cornell where I am the Meinig Family Professor in the Sibley School of Mechanical and Aerospace Engineering. I have taught engineering at various universities (Michigan/Stanford/Cornell) since 1992. I teach or have taught a variety of fluid mechanics classes at Cornell, including the MAE dept’s Introductory Fluid Mechanics class, the Intermediate Fluid Dynamics class, and two different classes on Microfluidics and Nanofluidics.

Professor Kirby Bot is my chatbot that answers fluid mechanics questions. Ashley Son and I developed it in 2024. There are of course many other chatbots, and many of them can answer fluid mechanics questions. Other chatbots annoy me because I think their answers are so often incorrect, as they repeat the wrong things from Wikipedia and the wrong things from YouTube over and over again. Professor Kirby Bot is powered by my notes, textbooks, message board responses, lectures, and videos, and so it talks more like me than other chatbots, which means I think its answers are usually right. And Professor Kirby Bot uses notation that matches my textbook “How Fluid Machines Work: an Introduction to Fluid Mechanics”, which we use in MAE3230 at Cornell. So if you are using that textbook, the symbols and terminology match. Professor Kirby Bot will also tell you what part of the textbook to read to learn more about the topic you are asking about.

Also, I check Professor Kirby Bot’s answers, so if one of Professor Kirby Bot’s answers has a little “Verified by Prof K” mark on it, it means I read its answer and I think it is correct.

How to get answers on Ask Professor Kirby
How do I know when I can use Bernoulli for pipe flow
Advance ratio and wingtip ratio
How do rotameters work?
How do I know when I can use Bernoulli for pipe flow
Area vel relation for quasi 1d flow
What is velocity potential
P0 vs p infinity
Navier stokes
Stagnation relations
Stages in pumps
Momentum flux vector
Airfoils and pressure
How to speed up flow
Sphere rotating in a flow
Stability
What is considered a high Reynolds number for a carburetor to assume steady inviscid flow?
Gamma
Free jet
Aeolian harp
Stall
Matrix vs. tensor
Inviscid flow equations
Drag force dependence on U
What sinks and what floats
Causes of shock waves
Curl vs. circular orbit
Sailboats
Perfectly Expanded Nozzle
Altimeter
Sailboats
Reynolds transport theorem
Normal Shock
Supersonic aircraft
How Planes Fly
Tank exiting speed
Aircraft mach no
Altimeters
Head per stage
Quasi 1D flow equations
Faucet
Tank draining
Drag racer parachute
Separation and Normal Streamline
Rocket Nozzle geometry
Number of Poles in an AC Motor
Irrotational Flow vs Circulation
Pressure and Nozzle Length
Carburetor Density question
Pump power scaling
Propeller thrust coefficient
Propeller performance
Pump specific speed
Pump design
Potential flow solution
Friction
Turbine Specific Speed Meaning
Multi-stage pumps
Specific speed doesn't match
Conservation equations for quadcopter
U Bar
Mach number
Conservation of mass velocity fields
Stored energy in water
Floating cube stabiltiy
Floating cube stabiltiy
Nozzle Design
Conservation of mass calcs
Sink flows
Siphons
Flow regimes
Force on block
Faucet
Tank pressure
Helicopters
Mach 1 at the throat
Unshrouded axial flow pump
I don't get this question
Flowfield in cylidrical coords
Faucet
Faucet
Potflow
Nozzle Shape
Thermodynamic efficiency vs efficiency
Velocity field calcs
Dot product
Axial flow or radial flow
Contianer filling
Vinturi wine aerator
Laminar vs turbulent
Sonic Fluid
Pressure conversions
Carburetor
Velocity potential and streamfunction
Prevent normal shock in rockets
Air compressibility
Test tube
Faucet
Compressible flow equations
Separation
Laminar flow through circular pipe
Couette flow
Free-surface effect
Test tube
Heat transfer in pipes
Boundary layers and separatoin
Carburetor vs bearing
What is stagnation pressue
Conical nozzle
Force on glass sturcture
Jetpack
Differential vs integral conservation equations
Pressure coefficients
Squeeze bulb siphon
Unit vector notation
Water jet cutter
Homework problem
Pressure loss equations
Turbomachine equations
Hydrostatics equations
Thin airfoil theory
Shower head problem
Log float
Tension in string holding post
Log float
Log float
Loading a barge
Log float
Journal bearing -- how it works
Reynolds number definition
Irrotational flow
Dynamic vs displacement
Boundary layer shear force
Pipes, containers, and airfoils
Siphon performance
Jetpack
Exam problem
Compressed air flow
DC motor powered pump
Liquid rocket engine
Flow measurement of helium
Lamb vector
Derivation of Prandtl's Boundary Layer Equation
Lamb vector
Derivation of Prandtl's Boundary Layer Equation
Oil viscosity
Flapping Flight
Complex Variable Analysis
Flapping Flight Homework
Complex Variable Analysis
Flapping Flight Homework
Blasius' Solution to Prantdl's Boundary Layer Equation
Matrix representation
Coanda effect
Coanda effect
Rocket
Hollow floating cube
Velocity gradient
Velocity gradient
Velocity gradient
Acceleratoin to takeoff
Particle acceleration
Velocity gradient
Velocity gradient
Velocity gradient
The Bernoulli equation in irrotatoinal flows
Storm water pumping problem
Ansatz
Torpedo
Momentum flux term
Sports balls
Cooling port
Wind tunnel speed
Filling a bucket
Term in navier stokes
Rocket
Rocket
Fully developed flow
Double checking my notation
Glyceri
Homework problem on bondary layers
Glyceri
Glyceri
Nondim missle
Dimensionless coefficients
Oil through a pipe
Nondim missle
Nondim missle
Nondim missle
Effect of wind on fuel consumption
Viscometer calc
Propeller nondimensionalization
Fan efficiency calculations
Material derivative and RTT
Baseball
Ultimate Air Trap design
Baseball
Fan efficiency calculations
Propeller nondimensionalization
Nondimensionalizing Navier-Stokes
Viscometer calc
Viscometer calc
Fish tank
Fluid specific gravity
Cordier diagram
Vacuum clearner pump
Cordier diagram
Nondimensionalizing Navier-Stokes
Oil through a pipe
Temperature rise in venturi
Torque converter design
Kutta condition (in spanish)
Substantial derivative
Pressure in column
Pressure in accelerating tank
Torque converter design
Temperature rise in venturi
Ultracentrifuge
Half full pipe flow
Half full pipe flow
Half full pipe flow
Incompressible flow
Pump efficiency
Stormwater design
Stormwater design
Viscosity vs friction
Vane pump vs gear pump
Surface roughness
Head definitions
Energy dissipation
Efficiency of turbine model
Parshall flume?
Hoover dam reaction turbines
Hydraulic jump
Parshall flume?
Efficiency of turbine model
Flow factor, flow cefficient
Spd of sound
Spd of sound
Flag pole
Actuator disk definition
Lubricating oil pump
Lubricating oil pump
Lubricating oil pump
Flow between reservoirs
Drag on sailboat keel
Speed measurement
Turbine scaling
Sf drag
Sf drag
Sf drag
Surface roughness
Vortex
Expansion loss coefficient
Hydraulic jump
Drag on sailboat keel
Hydraulic jump
Drag on sailboat keel
Expansion loss coefficient
Expansion loss coeff vs free jet
Radial flow pump
Momentum flux dyadic
Head losses in pipes
Speed of sound meaning
Valve question
Losses in elbows
Superposition
Kutta condition
Flow meters
Aircraft wing pressure
Dyson hair dryer
Streamline coordinates
Pressure and energy
Quadratice resistance coefficient
Dissipation
Boundary layer thicknesses
Paper towel
Hwk problem -- plates
Nonnewtonian fluids
Why nozzles
Viscosity symbol
Streamlines, forces, speed, pressure
Hot air balloon questions
Perfectly expanded nozzles