Andra TOFAN-NEGRU

Dr. Andra TOFAN-NEGRU


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 March 2023 in Drones
Verified
Journal Article
Open access
PDF file
ATAndra TOFAN-NEGRU
Andra TOFAN-NEGRU
ASAmado George Stefan
Amado George Stefan
LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
Ionica OncioiuIonica Oncioiu
Ionica Oncioiu
The aim of the paper is to validate the analytical–numerical analysis method regarding the operating regime of the propellers of a quadcopter. The research aims to mark the flow areas whose numerical results differ from the experimental ones and to investigate the possible reasons for the discrepancies between the values. The paper presents the determination of the air velocity produced by the rotational movement of a quadcopter propeller for a stationary position of the drive motor. The velocities were determined both experimentally at various points located below the propeller plane using hot-wire anemometric probes and numerically using a time-lapse simulation with a rotating sliding table. The numerical simulations carried out consisted of the determination of the time variation of the velocity distribution developed by the propeller in the rotational movement for the different operating (power) cycles of the engine. In addition, a technique that utilizes reverse engineering to determine the propeller profile, the anemometric probe calibration, and the average velocity values measured at various points below the propeller plane for engine operating regimes that range from 60 to 90% are also presented.

18 December 2023 in Studies in Informatics and Control
Verified
Journal Article
Closed access
ATAndra TOFAN-NEGRU
Andra TOFAN-NEGRU
ASAmado George Stefan
Amado George Stefan
CVCristian Vidan
Cristian Vidan

13 December 2024 in Drones
Verified
Journal Article
Open access
PDF file
ATAndra TOFAN-NEGRU
Andra TOFAN-NEGRU
ASAmado George Stefan
Amado George Stefan
MCMaria Casapu
Maria Casapu
This research focuses on the dynamic response analysis of a quadcopter arm without an adapter mounted and with aerodynamic profile adapters mounted to enhance drone performance. Nine different adapters were simulated to assess their impact on the arm’s dynamic behavior during various motor operating regimes. The pressure force distribution from the airflow around the quadcopter arm was analyzed to determine the optimal adapter configuration. Numerical simulations revealed the best geometry for the adapter, which significantly reduced maximum displacement amplitudes compared to the non-adapter arm. The study also examined the effects of static imbalance from the rotor-propeller assembly, leading to the calculation of an eccentricity value of 0.022 mm for inertial force application. Experimental tests validated the numerical findings, with laser vibrometer measurements confirming improved dynamic responses with Adapter 8 across most operating regimes. Overall, the study shows the advantages of using better aerodynamic designs in quadcopter arms to improve stability and performance, contributing to advancements in drone technology through improved structural designs.