# Hemyar Alharazi > Multidisciplinary engineer working across aeronautical engineering, UAV operations, artificial intelligence and full-stack software development. Based in Riyadh, Saudi Arabia. This is the official professional website of Eng. Capt. Hemyar Alharazi, published in English and Arabic. Content here is maintained by its owner and is the authoritative source for his work, services and publications. - Name: Eng. Capt. Hemyar Alharazi (Arabic: حمير الحرازي) - Also known as: Captain Hemyar - Role: Aeronautical Engineer · UAV & AI Specialist · Full-Stack Developer - Based in: Riyadh, Saudi Arabia - Languages: English, Arabic - Official website: https://captainhemyar.tech (English) and https://captainhemyar.tech/ar (Arabic) - Email: AeroTech2017@gmail.com - Contact form: https://captainhemyar.tech/contact - Profiles: https://in.linkedin.com/in/hemyar-alharazi-1b812b168, https://www.youtube.com/@hemyaral-harazi8316, https://www.facebook.com/profile.php?id=100016041426130 ## Main pages - [About](https://captainhemyar.tech/about): background, approach and career summary - [Expertise](https://captainhemyar.tech/expertise): areas of specialisation - [Services](https://captainhemyar.tech/services): what he can be engaged for - [Portfolio](https://captainhemyar.tech/portfolio): projects and case studies - [Research & Publications](https://captainhemyar.tech/research): technical notes and white papers - [Insights](https://captainhemyar.tech/blog): articles - [Knowledge base](https://captainhemyar.tech/knowledge): reference articles - [Experience](https://captainhemyar.tech/experience) - [Education](https://captainhemyar.tech/education) - [Certifications](https://captainhemyar.tech/certifications) - [CV](https://captainhemyar.tech/cv): printable curriculum vitae - [Contact](https://captainhemyar.tech/contact) ## Expertise - [Aerospace & Aeronautical Engineering](https://captainhemyar.tech/expertise/aerospace-engineering): Aircraft design and analysis across aerodynamics, structures, systems and flight mechanics, supported by simulation and engineering computation. - [UAV & Drone Technology](https://captainhemyar.tech/expertise/uav-drone-technology): Certified UAS flight operations together with UAV systems knowledge: airframes, propulsion, autopilots, sensors, payloads, navigation and ground control. - [Engineering Design & Simulation](https://captainhemyar.tech/expertise/engineering-design-simulation): Three-dimensional modelling and engineering analysis using CATIA, SolidWorks, NX CAD and AutoCAD, with simulation in ANSYS CFD/CFX and computation in MATLAB. - [Artificial Intelligence & Automation](https://captainhemyar.tech/expertise/artificial-intelligence): Applying generative AI, language-model integration and workflow automation to real operational problems rather than demonstrations. - [Software & Web Development](https://captainhemyar.tech/expertise/full-stack-development): Designing and building web platforms end to end — interface, application logic, data model, API surface and deployment. - [Aviation Technology & Operations](https://captainhemyar.tech/expertise/aviation): Aviation systems and operations, including production practice, compliance with aviation standards, and the regulatory context around flight activity. - [Digital Marketing & Growth](https://captainhemyar.tech/expertise/digital-marketing): Search and performance marketing grounded in measurement: SEO, paid search and social, analytics instrumentation and conversion optimisation. - [Technical Content & Communication](https://captainhemyar.tech/expertise/technical-content): Technical writing that makes engineering work legible: documentation, educational material and research communication in English and Arabic. ## Services - [UAV Survey & Aerial Inspection](https://captainhemyar.tech/services/uav-survey-and-inspection): Planned drone missions that turn a site into measurable data — orthomosaics, elevation models and inspection imagery you can act on. - [Aerodynamic Analysis & CFD](https://captainhemyar.tech/services/aerodynamic-analysis-cfd): Computational fluid dynamics for lift, drag and stability questions — with the mesh study and validation that make the numbers worth quoting. - [Aircraft & UAV Design Support](https://captainhemyar.tech/services/aircraft-and-uav-design): Conceptual and preliminary design — sizing, configuration trade studies, structural checks and the weight budget that keeps them honest. - [Applied AI & Automation](https://captainhemyar.tech/services/ai-and-automation): Machine learning and automation aimed at a decision that changes — scoped against a baseline, measured honestly, and shipped into a real workflow. - [Web & Software Development](https://captainhemyar.tech/services/web-and-software-development): Bilingual web platforms and internal tools built to be maintained — accessible, fast, and documented well enough to hand over. - [Technical Documentation & Training](https://captainhemyar.tech/services/technical-documentation-training): Engineering documents and training material written for the person who has to use them under time pressure. ## Research & Publications - [Demonstrating Accuracy in UAV Photogrammetry: Why Checkpoints, Not Control Points, Tell the Truth](https://captainhemyar.tech/research/uav-photogrammetry-accuracy-checkpoints): Accuracy figures in drone survey reports are often residuals on ground control points — numbers that describe how well the software fitted the constraints it was given, not how accurate the model is. This note sets out… - [CFD for Small UAV Wings at Low Reynolds Numbers: A Verification and Validation Checklist](https://captainhemyar.tech/research/low-reynolds-cfd-verification-validation): Small UAV wings often operate at chord Reynolds numbers where laminar separation bubbles and transition dominate the aerodynamics — exactly the regime where default CFD settings mislead. This note gives a practical… - [Planning Multirotor Endurance in Hot Climates: Density Altitude, Battery Temperature and Honest Margins](https://captainhemyar.tech/research/multirotor-endurance-hot-climates): Manufacturer endurance figures are measured in benign conditions. In a hot summer — typical of the Arabian Peninsula — lower air density raises the power needed to hover while high temperatures constrain the battery… - [Predictive Maintenance in Aviation: Where Machine Learning Earns Its Place — and Where It Does Not](https://captainhemyar.tech/research/predictive-maintenance-aviation-machine-learning): Machine learning promises earlier fault detection and fewer unscheduled removals, but aviation maintenance is a regulated, safety-critical process with sparse failure data. This paper sets out when a predictive model… - [Dust and Sand in Desert UAV Operations: Effects on Propulsion, Sensors and Maintenance](https://captainhemyar.tech/research/dust-and-sand-desert-uav-operations): Fine dust and blowing sand shorten the life of small UAVs in ways that rarely appear in a specification sheet. This note reviews the main mechanisms — propeller leading-edge erosion, particle ingress into motors and… - [Building Bilingual Arabic–English Web Platforms for Engineering Content: An RTL-First Approach](https://captainhemyar.tech/research/bilingual-rtl-engineering-web-platforms): Engineering organisations in the region publish for readers who switch between Arabic and English, often within one document. Treating Arabic as a translated afterthought produces broken layouts, mixed-direction numbers… ## Insights - [Technical Overview of Leading UAV Platforms for Engineering Applications](https://captainhemyar.tech/blog/technical-overview-leading-uav-platforms-engineering): This article provides a detailed technical overview of prominent unmanned aerial systems (UAS) used in engineering fields. It covers platform types, capabilities, and selection criteria relevant to engineering… - [Simulation Does Not Replace Engineering Judgement](https://captainhemyar.tech/blog/engineering-judgement-and-simulation): Software will happily solve the wrong problem to twelve significant figures. The engineer's job is deciding which problem is worth solving — and knowing when the answer is implausible. - [Five Questions to Ask Before Commissioning a Drone Survey](https://captainhemyar.tech/blog/what-clients-should-ask-before-a-drone-survey): Aerial survey quotes vary enormously for work that sounds identical. These five questions expose what you are actually being offered — and protect you from data that cannot support the decision you bought it for. - [AI That Earns Its Place](https://captainhemyar.tech/blog/ai-that-earns-its-place): The interesting question is rarely whether machine learning can be applied, but whether it should be. A surprising number of problems are better served by a rule, a form, or a fixed process. ## Arabic version - [الصفحة الرئيسية](https://captainhemyar.tech/ar): the whole site in Arabic - [الأبحاث والمنشورات](https://captainhemyar.tech/ar/research) - [الخدمات](https://captainhemyar.tech/ar/services) - [نبذة](https://captainhemyar.tech/ar/about) ## Optional - [Full text for language models](https://captainhemyar.tech/llms-full.txt): every published article and page summary in one Markdown file - [How Lift Is Actually Generated](https://captainhemyar.tech/knowledge/how-lift-is-actually-generated): The equal transit-time story is wrong, and the popular Bernoulli explanation is incomplete. What actually produces lift is flow turning… - [Why Reynolds Number Dominates Small UAV Design](https://captainhemyar.tech/knowledge/reynolds-number-small-uav-design): Small UAVs operate in a regime where aerofoils designed for full-scale aircraft quietly stop working. Understanding why prevents a class of… - [Load Paths: Why Structures Fail Where They Do](https://captainhemyar.tech/knowledge/load-paths-and-structural-failure): Structural failures are rarely where the stress is highest in the raw sense. They are where load concentrates, where stiffness changes… - [Fixed-Wing, Multirotor or VTOL: Choosing a UAV Configuration](https://captainhemyar.tech/knowledge/choosing-a-uav-configuration): Configuration is the decision that constrains every other one. It should follow from the mission — area, endurance, take-off space and… - [Planning a Photogrammetry Flight That Meets Its Accuracy Target](https://captainhemyar.tech/knowledge/planning-a-photogrammetry-flight): Ground sample distance, overlap and control points are not independent settings. Choosing them from the accuracy the deliverable requires… - [Scoping a Machine Learning Project So It Survives Contact With Reality](https://captainhemyar.tech/knowledge/scoping-a-machine-learning-project): Most machine learning projects fail before any modelling happens — on a vague objective, an unavailable label, or a baseline nobody… - [Technical SEO for Bilingual Sites: hreflang, Canonicals and the Mistakes That Cost Traffic](https://captainhemyar.tech/knowledge/technical-seo-for-bilingual-sites): A bilingual site can compete twice or compete against itself. The difference comes down to a small number of technical signals that are… - [Understanding Drag: Where It Comes From and What Actually Reduces It](https://captainhemyar.tech/knowledge/understanding-aircraft-drag): Drag is not one phenomenon but several, each responding to different design changes. Knowing which component dominates your configuration… - [Composite Structures: What Changes When the Material Has a Direction](https://captainhemyar.tech/knowledge/composite-structures-in-aerospace): Composites are not simply lighter metals. Directional properties, layup-dependent behaviour and failure modes with no metallic equivalent… - [Mesh Independence: The Study That Makes CFD Credible](https://captainhemyar.tech/knowledge/cfd-mesh-independence): A CFD result without a grid convergence study is an opinion with colour maps. Here is how to demonstrate that your answer belongs to the… - [Choosing a Turbulence Model Without Guessing](https://captainhemyar.tech/knowledge/choosing-a-turbulence-model): No turbulence model is universally best. Each encodes assumptions that hold for some flows and fail for others — and the failures are… - [Parametric CAD: Modelling for the Change That Is Coming](https://captainhemyar.tech/knowledge/parametric-cad-modelling-for-change): A CAD model is not a picture of a part — it is a set of decisions about how that part may change. Models built without that in mind become… - [Finite Element Analysis You Can Defend in a Review](https://captainhemyar.tech/knowledge/trustworthy-finite-element-analysis): FEA produces a colourful answer for any input, valid or not. The discipline is in the checks around it — boundary conditions, convergence… - [Estimating Endurance for an Electric UAV Without Fooling Yourself](https://captainhemyar.tech/knowledge/battery-endurance-electric-uav): Datasheet capacity, usable capacity and delivered capacity are three different numbers. Endurance estimates that ignore the difference are… - [Pre-Flight Discipline: Managing Risk Before the Rotors Turn](https://captainhemyar.tech/knowledge/preflight-checks-and-operational-risk): Most drone incidents trace back to something knowable before take-off. A written, followed checklist is unglamorous and is the single… - [UAV Regulation: The Concepts Behind Every Rulebook](https://captainhemyar.tech/knowledge/uav-regulation-fundamentals): National rules differ, but they are built from a shared vocabulary — operational categories, risk assessment and airspace classification… - [Computer Vision for Inspection: Where It Works and Where It Fails](https://captainhemyar.tech/knowledge/computer-vision-for-industrial-inspection): Automated visual inspection succeeds or fails on data and imaging conditions long before model architecture matters. The projects that… - [Building Arabic–English Interfaces That Aren't an Afterthought](https://captainhemyar.tech/knowledge/building-bilingual-arabic-english-interfaces): Right-to-left support fails when it is bolted on at the end. Treating direction as a property of the layout system from the first commit… - [Web Performance That Survives Real Networks and Real Devices](https://captainhemyar.tech/knowledge/web-performance-on-real-networks): A site that feels instant on a developer's machine can be unusable on a mid-range phone over mobile data. Performance is a budget you set… - [Building Technical Authority Through Content People Actually Use](https://captainhemyar.tech/knowledge/content-strategy-for-technical-authority): Technical credibility is not built by publishing frequently. It is built by being genuinely useful on a narrow set of questions, and by… - [Sitemap](https://captainhemyar.tech/sitemap.xml)