Thursday, October 21, 2021

Lists of Some Articles By Topic Area

Update 12-2-2022:  two ramjet articles added to that topic list,  this color.

Update 9-5-2022:  some recent articles added to the lists,  this text color.

Update 10-1-2022:  some others added,  this color.

Update 10-30-2022a couple added,  this color.


I was once an all-around ramjet design,  development,  and test engineer,  among many other things,  including rocket work.  This was mostly at a plant in McGregor,  Texas,  once known as Rocketdyne or Hercules.  Part of that reservation is where SpaceX tests rockets now. 

I did just about everything there was to do,  for this ramjet work.  There are very few indeed with knowledge and experience this comprehensive,  I was definitely not a narrow specialist!  But my knowledge and abilities,  in each of all these different specialty disciplines,  was actually quite substantial and deep!  

My design analyses usually took the form of custom hand-calculations,  not just sitting there blindly running other people’s computer codes.  (Although,  I did use computer codes,  and even wrote some myself.)  I have informally published several articles on my blog site that describe how some of this ramjet work was done.

Ramjet & Closely-Related Articles (there are others,  but these are the best):

12-2-2022            The Unchoked Gas Generator As A Throttle For Gas Generator-Fed Ramjets

12-1-2022            How Ramjets Work

10-30-22              Plasma Sheath Effects in High Hypersonic Flight

6-1-22                  About Hypersonic Vehicles

11-2-21                The “Warm Brick” Ramjet Device (nonpropulsive application to an infrared decoy)                                 [also the 11-2-21 update to this catalogue list]

10-1-21                Use of the Choked Pintle Valve for a Solid Propellant Gas Generator Throttle

8-2-21                  The Ramjet I Worked On the Most

7-1-21                  Another Ramjet I Worked On

11-9-20                Fundamentals of Inlets

3-3-20                  Ramjet Flameholding

2-16-20                Solid Rocket Analysis (applies to ramjet for boosters)

2-4-20                  One of Several Ramjets That I Worked On

1-2-20                  On High-Speed Aerodynamics and Heat Transfer

11-12-18              How Propulsion Nozzles Work

7-4-17                  Heat Protection Is the Key to Hypersonic Flight

6-12-17                Shock Impingement Heating Is Very Dangerous

12-10-16              Primer on Ramjets

12-21-12              Ramjet Cycle Analyses

These are located on,  along with many others on a wide variety of subjects. 

There is a navigation tool on the left of that page.  For the article you want,  you only need its publication date and its title.  Use the navigation tool:  click on the year,  then the month.  Then click on the title if you need to.  The data you need are in these lists.

If you click on one of the figures,  you can see all of them enlarged.  You see nothing but the figures,  though.  There is an “X-out” from this view,  upper right of screen.

At the end of any given article,  there is also a list of search keywords assigned to it.  If you click on “ramjet”,  you will only see the articles bearing that keyword.  The same is true of the other keywords.

Here follows a photo of one of the ramjets I worked on:  ASALM-PTV.  It is hanging under the wing of an A-7 Corsair-II,  an aircraft my father designed.  I always considered this photo a sort of “family portrait”. 


ASALM-PTV Ramjet Vehicle Underwing of A-7 Corsair-II

Some of those ramjet articles overlap with the next list.  That next list is of aerothermodynamics and heat transfer-related articles.  Some of these relate to high-speed atmospheric flight,  and others to atmospheric entry from space.  Those two scenarios are quite different,  in that atmospheric flight is a steady-state equilibrium problem,  while atmospheric entry is mostly a transient heat-sinking problem.  The search keyword for these is “aerothermo”.  Clearly,  I was adept at multiple specialties.

Aerothermodynamics & Heat Transfer Articles:

9-18-22                Plasma Sheath Effects in Hypersonic Flight

7-3-22                  Early High-Speed Experimental Planes

6-1-22                  About Hypersonic Vehicles

4-1-20                  Entry Heating Estimates

1-2-20                  On High-Speed Aerodynamics and Heat Transfer

1-9-19                  Subsonic Inlet Duct Investigation

1-6-19                  A Look At Nosetips (Or Leading Edges)

1-2-19                  Thermal Protection Trends For High-Speed Atmospheric Flight

11-12-18              How Propulsion Nozzles Work

7-4-17                  Heat Protection Is the Key to Hypersonic Flight

6-12-17                Shock Impingement Heating Is Very Dangerous

11-17-15              Why Air Is Hot When You Fly Fast

8-4-13                  Entry Issues

3-18-13                Low-Density Non-Ablative Ceramic Heat Shields

1-21-13                BOE Entry Analysis of Apollo Returning From the Moon

1-21-13                BOE Entry Model User’s Guide

8-19-12                Ballute Drag Data

8-19-12                Blunt Capsule Drag Data

7-14-12                “Back Of the Envelope” Entry Model

I was also a rocket propulsion engineer,  mostly in solid composite propellants.  However,  from the chamber outlet through the nozzle,  the ballistics of all rockets are the same,  including liquid propellant rockets.  If you can allow for any gas bled off and dumped overboard for turbopump operation,  then the very same ballistics apply,  right down to the chamber pressure vs flow rate calculation. 

Further,  the estimation of vehicle performance from the simple rocket equation can be made quite accurate,  if you know how to apply “jigger factors” in the appropriate places for gravity and drag losses,  and if you know what values of these “jigger factors” to apply.  I have been very successful at doing this kind of work. The following list shows that,  and mostly shares the “launch” and “space program” keywords.  While still a graduate student,  I spent a summer doing advanced configuration and mission work at what was then LTV Aerospace,  working on its "Scout" 4-stage solid satellite launcher. 

Rocket Ballistics and Rocket Vehicle Performance articles:

10-27-22              Getting to Low Earth Orbit  (vertical ballistic launch versus lifting ascent)

10-1-22                Rocket Engine Calculations (how to rough-out or reverse-engineer, ex: Raptor-2)

9-7-22                  Two-Stage Reusable Spaceplane Rough-Size (VTO HL both stages)

8-4-22                  Engineering Lander/Rover for Mars

5-1-22                  Investigation:  "Big Ship" Propellant From the Moon vs From Earth (added to list as part of Update 5-1-22)

4-2-22                  Earth-Mars Orbit-to-Orbit Transport Propulsion Studies (added to list as part of Update 5-1-22

2-1-22                  A Concept for an On-Orbit Propellant Depot

8-18-21                Propellant Ullage Problem and Solutions

3-15-21                Reverse Engineering Estimates: Starship Lunar Landings

3-9-21                  Reverse-Engineering Starship/Superheavy 2021

3-5-21                  Fundamentals of Elliptic Orbits (delta-vee requirements)

2-9-21                  Rocket Vehicle Performance Spreadsheet (rocket vehicle performance)

7-13-20                Non-Direct to the Moon with 2020 Starship

7-5-20                  How the Spreadsheet Works (Starship to Mars)

7-5-20                  2020 Starship/Superheavy Estimates for the Moon

7-3-20                  Cis-Lunar Orbits and Requirements

6-21-20                2020 Starship/Superheavy Estimates for Mars

5-25-20                2020 Reverse Engineering Estimates for Starship/Superheavy

2-16-20                Solid Rocket Analysis (solid ballistics & more)

11-21-19              Interplanetary Trajectories and Requirements

10-22-19              Reverse-Engineering the 2019 Version of The Spacex “Starship” / “Super Heavy” Design

9-26-19                Reverse-Engineered “Raptor” Engine Performance (liquid ballistics)

9-16-19                Spacex “Starship” as a Ferry for Colonization Ships

9-9-19                  Colonization Ship Study

11-12-18              How Propulsion Nozzles Work (rocket, ramjet, & turbine; plain & free-expansion)

9-11-18                Velocity Requirements for Mars

8-23-18                Back-of-the-Envelope Rocket Propulsion Analysis (rocket vehicle performance)

4-17-18                Reverse Engineering the 2017 Version of the Spacex BFR

10-23-17              Reverse-Engineering the ITS/Second Stage Of the Spacex BFR/ITS System

3-18-17                Bounding Analysis for Lunar Lander Designs (rocket vehicle performance)

3-6-17                  Reverse-Engineered “Dragon” Data (rocket vehicle performance)

8-31-13                Reusable Chemical Mars Landing Boats Are Feasible (rocket vehicle performance)

In 2009,  I attended an asteroid defense conference in Granada,  Spain,  as a poster paper presenter.  I have since written some articles about asteroid defense.  Unfortunately,  the asteroid defense capability picture hasn’t changed much since my 2009 attendance at that conference.  Again,  the latest are the best and most up-to-date.   Be aware that “NEO” (Near Earth Object) includes comets as well as asteroids as threats.  Comets may be the more difficult to defend against,  because of the surprise nature of the detection and orbits.  These articles all share the “asteroid defense” keyword.

Asteroid Defense Articles:

8-30-20                Asteroid Threats  (current status assessment:  not good)

6-3-20                  On the Manned Spacex Launch

7-14-19                Just Mooning Around (asteroids plus Mars)

12-13-13              Mars Mission Study 2013 (what takes you to Mars takes you to asteroids)

4-21-09                On Asteroid Defense and a Good Reason for Having National Space Programs

I have also applied my wide-ranging knowledge to the problems of atmospheres to breathe while in space,  and the kinds of spacesuits that might best serve our needs.  Again,  the latest is the best and most up-to-date.  But I have been looking into these issues for some time,  as indicated by the dates on these articles.  These all share the “spacesuit” keyword.

Space Suits and Atmospheres Articles:

1-2-22                  Refining Proposed Suit and Habitat Atmospheres (update 1-2-22) best case and easiest-to-remember cases,  plus an independent estimate of the utter min suit pressures feasible

1-1-22                  Habitat Atmospheres and Long-Term Health (update 1-1-22)  adds a long term hypoxia criterion for the habitat in addition to short term criteria for the min-P suit

3-16-18                Suit and Habitat Atmospheres 2018

11-23-17              A Better Version of the MCP Spacesuit?

2-15-16                Suits and Atmospheres for Space

1-15-16                Astronaut Facing Drowning Points Out Need for Better Space Suit

11-17-14              Space Suit and Habitat Atmospheres

2-11-14                On-Orbit Repair and Assembly Facility

12-13-13              Mars Mission Study 2013

1-21-11                Fundamental Design Criteria for Alternative Space Suit Approaches

One of my favorites is the MCP (mechanical counter pressure) version of the spacesuit.  This was pioneered by Dr. Webb in the 1960’s as a possible suit for the Apollo missions to the moon.  It is not a full pressure suit at all,  but essentially a tight garment that simply squeezes the body.  It is porous,  so that you sweat right through it to cool,  just like ordinary street clothing.  But this design was tested quite successfully in 1968 for 30 minutes in a vacuum chamber,  at way above the equivalent “vacuum deathpoint” altitude.  Photo follows:

Webb’s MCP Space Suit:  Helmet,  Backpack,  and Supple Garment Total 85 Lbs

The reason why I like this approach over Dava Newman's designs is that Webb's designs are essentially vacuum-protective underwear that can be easily laundered.  Over them you wear whatever unpressurized clothing you need for protection from from heat,  cold,  and mechanical hazards.  All of these are separate,  easily laundered items.  I think the "one garment that does everything" approach,  that we have been using since about 1960,  is wrong.  "Mix and match" is way more flexible.

Besides vacuum death and microgravity disease,  there is also a radiation hazard to worry about in space.  But,  it is not quite what you think:  there are two completely different hazards to worry about.  On Earth,  we have two kinds of protection:  the atmosphere,  and the magnetic field.  In low Earth orbit,  we have only the magnetic field.  Outside the magnetic field,  going to the moon or anywhere else,  there is no protection.  Yet these things can be quantified,  and some of it shielded fairly effectively.  What got me started on this topic were the dangers posed by the nuclear disaster in Fukushima,  Japan.  Keyword “radiation”.

NASA has since lowered its career exposure limits below the older values I had obtained from them.  That avoids the slight chance of cancer late in life due to galactic cosmic ray exposure over long times in space.  But,  it makes passive shielding design bulkier,  heavier,  and more difficult to design.  It's really a trade-off.  However,  NASA still has not faced up to the erratic but intense floods of radiation from solar eruptions.  They haven't yet killed a crew from this,  although they came close to that during Apollo.  But if they don't address this,  they will kill a crew,  once we move out beyond the Van Allen belts,  and try to stay there.  That includes the return to the moon.  

Radiation Hazard Articles:

10-5-18                Space Radiation Risks:  GCR vs SFE

4-11-15                Radiation Risks for Mars Trip

5-2-12                  Space Travel Radiation Risks

3-24-11                Radiation and Humans

3-17-11                Follow-Up On the Japan Nuclear Crisis

3-15-11                On the Nuclear Crisis In Japan

On a lighter note,  I have long been interested in pulsejet engines,  especially valveless pulsejets.  While teaching math at TSTC,  Waco,  I became involved with mentoring a student who was also interested in pulsejets.  I and a colleague assisted this student in making his own valveless pulsejet engines,  which attention and involvement also turned this student into an “A” student in math!  Keyword “pulsejet”.

That student built a small engine that eventually pushed an old golf cart around,  and then a much bigger engine which we together fired up out here on my farm homestead.  Photos of the two engines follow:

Smaller Student-Built Valveless Pulsejet Engine (Later Pushed a Golf Cart)

Larger Student-Built Valveless Pulsejet Engine

Pulsejet Articles:

5-20-12                Recommended Broad Design Guidelines For Valveless Pulsejet Combustors

4-30-12                Big Student Pulsejet an Even Larger Hit at TSTC

3-6-12                  Student Pulsejet a Hit at EAA Meeting

11-12-11              Student Pulsejet Project

I have been interested in ethanol fuels since my early days in college.  When I went to work for what is now Minnesota State University,  after my 20-year career in aerospace defense work ended,  I got more serious about it.  My next job was at Baylor University in Waco,  Texas,  and it dealt directly in alternative fuels for aircraft.  The scope of that included ethanol (and an ether) as piston-engine fuels,  and biodiesel-jet fuel blends as turbine fuels,  plus STC work with the FAA,  and also experimental engineering research work,  as well as classroom teaching. 

Not too long after leaving Baylor,  I began my own experimental engineering research at home,  using E-85 ethanol fuel,  and stiff ethanol blends,  in a variety of vehicles.  Those would include straight E-85 ethanol fuel in an old farm tractor and in an old-time air-cooled VW beetle,  plus stiff ethanol blends in a variety of completely-unmodified cars and 4-stroke lawn and garden equipment.  I basically recommend up to E-35 blend strength,  as a “drop-in” fuel,  for just about any 4-stroke piston engine. 

The keywords are “ethanol” and “old cars” for most of these articles.  Once again,  the latest is the best and most up-to-date.

Articles About Ethanol and Ethanol Blends in Vehicles:

9-1-21                  Making Stiff Blends At the Gas Pump

11-3-13                Aviation Alternative Fuel Compatibility Issues

11-2-13                An Update on Ethanol Fuel Use

8-9-12                  Biofuels in General and Ethanol in Particular

5-4-12                  Energy Storage: Batteries vs Unpressurized Liquid Fuels

6-12-11                Another Red-Letter Day

5-5-11                  Ethanol Does Not Hurt Engines

2-12-11                “How-To” For Ethanol and Blend Vehicles

11-17-10              Nissan Mileage Results on Blends

11-12-10              Stiff Blend Effects in Gasoline Cars

12-15-09              Red Letter Day:  Ethanol VW Experiment Complete

7-1-09                  Another Antique Comes Out of Storage

I have returned part-time out of retirement to help a friend with his auto repair business.  I was once ASE-certified as a condition of employment while teaching at Minnesota State in its Automotive and Manufacturing Engineering Technology department.  Before that,  I did most of my own automotive maintenance and repair work.  Accordingly,  I have posted some articles about basic car care,  plus one funny.  These all share the “old cars” and “fun stuff” keywords. 

I have since gone back into retirement.  My friend now has a real mechanic,  who knows more than I do,  and is much more experienced,  and faster. 

Automotive Care Articles:

8-22-22                Automotive Work (another "funny")

3-4-22                  Understanding Your Tires (added to this list as update 5-1-22)

12-3-20                Blinker Fluid (the “funny”,  and it is a sight gag)

8-20-20                Underhood Check

7-25-20                Taking Care of Car Batteries

When I returned to the rocket plant in McGregor for my second employment there,  the family and I acquired an old farm outside McGregor as our home.  We have been there ever since.  This place was largely covered in shin- to knee-high prickly pear cactus,  so thick there were few trails through it.  After grubbing it out of the house’s back yard with hand tools,  I decided there had to be a better way to do this cactus eradication. 

I tried a variety of mechanical drags behind my old farm tractor for some 15 years without success.  The results were always the same:  it looked better for a while,  but returned worse than ever before,  within months.  My neighbor was trying shredding at 1 inch off the ground.  Eventually that worked,  but required the neighbor to be out there shredding,  every single day,  the same ground over and over,  for 6 (or more) years.  The neighbor also tried spraying herbicides on one patch of ground,  which took 3 years to show results,  but then totally reinfested within another 2 years.

I then tried to build a “scooper-upper” out of scrap steel.  The idea was to bust the aboveground cactus loose from its roots,  and catch it on a tarp towed behind the “scoop-upper”,  for disposal in a burn pit.  It completely failed to work,  because when the tool hit the cactus and busted it loose from its roots,  it fell forward in front of the tool,  instead of backward onto the deck.  The tool then just ran over the top of the cactus debris.  I gave up in disgust when this failure-to-scoop happened.

I went back up a few months later to salvage the steel,  and saw something totally unexpected:  the cactus was dead and gone wherever the tool had been towed!  Grass was growing in the cow pasture where the cactus had been.  It did not take very long to understand that the aboveground cactus foliage had been crushed and damaged passing underneath the heavy tool,  such that the pads dried out and died,  before they could put down new roots from the thorn sites in contact with soil.  They had completely composted away over those months.

I “played” with this tool to get it just “right”,  and started killing acres of prickly pear quite effectively,  and with very little time and effort involved.  In fact,  I still have this very same experimental prototype,  and it still works today.  This prototype led to me filing a patent on the cactus tool in 2002. 

I revised the design to something more producible from real steel stocks,  and built two production prototypes that worked just as well as the original experimental prototype,  but were easier to build.  Then,  with the patent in hand as of 2004,  I began building and selling these tools to the public.  My first customer wouldn’t wait for a real production tool,  and insisted on buying one of the two production prototypes.  I still have the other one.  I still use it,  and it now serves as an experimental test bed for new features,  too.

As time went by,  it quickly became apparent that other folks had rockier land,  or land with tree stumps.  I changed the design twice,  to add a heavier stabilizing snout,  plus a “barge front” wedging surface to get over small rock outcrops.  This was quite successful,  and is embodied in the tools still built and sold today.

A close friend wanted to do cactus-killing for hire,  and bought a “one-off” design from me.  I also helped him build and modify a few more tools,  until the “commercial version” was defined:  a really tough snout,  a big “barge front”,  and retractable wheels to facilitate stepping over obstacles,  plus easier loading up ramps onto trailers. 

When that friend retired,  I revised his “commercial” design into something that used a common core tool chassis with my “homeowner grade” plain tool.  This common core chassis had the big barge front,  and used either a tough snout for the “plain tool”,  or a longer tough snout for the “hydraulic tool”,  that was also fitted with retractable wheels operated hydraulically.  I sell both versions to this very day.  Both are towed on a chain bridle behind a farm tractor’s drawbar.

I am working on a third version that could be an alternative implement affixed to the hydraulic boom of a skid-steer loader.  It uses an already-available “universal” adapter plate to accomplish this,  as a quick-change item.  There is nothing to report here yet about that project,  but the “plain” and “hydraulic” tools are well-described in a series of articles on “exrocketman” under the keyword “cactus-killing”. 

These two versions are shown in the photo,  with the plain tool in the foreground,  and the hydraulic tool in the background.

Foreground:  Plain Tool;  Background:  Hydraulic (Wheeled) Tool

The new skid-steer version has been tested and revised to a form that not only works,  but is more easily manufacturable.  It is now patent pending. 

Articles Related to Cactus Eradication:

2-9-17                  Time Lapse Proof It Works

7-30-15                New Cactus Tool Website

1-8-15                  Kactus Kicker Development

1-8-14                  Kactus Kicker:  Recent Progress

10-12-13              Construction of the Plain Cactus Tool

5-19-13                Loading Steel Safely (Cactus Tool)

12-19-12              Using the Cactus Tool or Tools

11-1-12                About the Kactus Kicker

12-28-11              Latest Production Version of the Kactus Kicker

 Update 12-1-2021:  these articles are more-or-less forensic analyses of various events:

12-1-21                The Seal Failure in the SRB That Doomed Challenger

12-10-20              Spacex Test Flight Results in Explosion

9-1-20                  On the Beirut Explosion

5-4-18                  Some Thoughts on the Anniversary of the West Explosion

11-1-14                Two Commercial Spaceflight Disasters in One Week

7-9-13                  On the Asiana 214 Crash

7-9-13                  On the Train Wreck in Quebec

4-18-13                Fertilizer Explosion in West,  Texas

9-23-11                Air Races,  Air Shows,  and Risks

6-3-10                  Plenty of Blame to Go Around for the Disaster in the Gulf

5-20-10                It really was the North Koreans who sank the South Korean ship

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