Improvement of the longitudinal aerodynamic model for general aviation aircraft with downwash and ground effect models

master's thesis

• Title (croatian): Unaprjeđenje uzdužnog aerodinamičkog modela aviona opće avijacije s modelom povijanja struje i utjecaja tla
• Author: Magdalena Vuković
• Mentor: Milan Vrdoljak (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-12-06, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Aviation, Rocket and Space Technology

Abstract

The Centre for Aviation at the ZHAW School of Engineering has been developing a flight
simulation model of the Piper PA-28-161 Warrior III for research purposes, based on data from
two flight test campaigns conducted by students. Previous work focused on estimating
aerodynamic parameters and improving the control force model but faced limitations in the flap
model, downwash effects, and ground effect representation.
This thesis addresses these issues by introducing a new single-slotted flap model using ESDU
methods, a new downwash model accounting for wing wake effects on the tailplane, and an
improved ground effect model for lift and pitching moment near the ground. These updates
enhance the simulation’s accuracy, particularly at low speeds with deployed flaps.
Despite limited flight test data for some configurations, the updated model demonstrates better
predictions of lift and pitching moment compared to the previous version. These improvements
provide a more realistic simulation of the PA-28’s performance and create a foundation for
future refinements.

Abstract (croatian)

Centar za zrakoplovstvo ZHAW škole strojarstva razvija model simulacije leta Piper PA-28-
161 Warrior-a III u istraživačke svrhe, temeljen na podacima prikupljenim tijekom dviju
studentskih letnih kampanja. Prethodni radovi bavili su se procjenom aerodinamičkih
parametara i poboljšanjem modela upravljačkih sila, no ostala su ograničenja u modelima
zakrilaca, efekta povijanja struje i efekta tla.
Ovaj rad fokusira se na ta ograničenja uvođenjem novog modela za zakrilca s jednim prorezom
koristeći ESDU metode, novog modela povijanja struje koji uključuje izračune gradijenta
povijanja struje, kuta povijanja struje i gubitka dinamičkog tlaka te poboljšanog modela efekta
tla za bolje prikazivanje promjena uzgona i momenta propinjanja tijekom polijetanja i slijetanja.
Unatoč ograničenim podacima za spuštene zakrilce i efekt tla, ažurirani model pokazuje bolju
točnost u simulaciji uzdužnog aerodinamičkog ponašanja, posebno pri malim brzinama.
Poboljšanja omogućuju realističniju simulaciju performansi PA-28 i pružaju temelj za daljnja
istraživanja.

• Keywords: Piper PA-28-161 Warrior III; flight simulation; aerodynamic model; downwash; ground effect; flaps; longitudinal aerodynamics; lift; drag and pitching moment coefficients
• Keywords (croatian): Piper PA-28-161 Warrior III; simulacija leta; aerodinamički model; efekt povijanja struje; efekt tla; model zakrilaca; uzdužna aerodinamika; koeficijenti uzgona i momenta propinjanja
• Language: english
• URN:NBN: urn:nbn:hr:235:127217
• Study programme: Title: Aeronautical Studies; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka zrakoplovnog inženjerstva (magistar/magistra inženjer/inženjerka zrakoplovnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-02-12 11:28:32